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HOME  UNIVERSITY  LIBRARY 
OF  MODERN  KNOWLEDGE 

No.  63 


Editors: 

HERBERT    FISHER,  M.A.,  F.B.A. 
Prof.   GILBERT    MURRAY,  Litt.D., 

LL.D.,  F.B.A. 
Prof.  J.  ARTHUR    THOMSON,  M.A. 
Prof.  WILLIAM    T.  BREWSTER,  M.A. 


THE  HOME  UNIVERSITY  LIBRARY 
OF  MODERN  KNOWLEDGE 

i6mo  cloth,  50  cents  net,  by  mail  56  cents 
SCIENCE 

Already  Published 

ANTHROPOLOGY By  R.  R.  Marett 

AN    INTRODUCTION   TO 

SCIENCE By  J-  Arthur  Thomson 

EVOLUTION By  J.  Arthur  Thomson  and 

Patrick  Geddes 

THE  ANIMAL  WORLD By  F.  W.  Gamble 

INTRODUCTION     TO     MATHE- 
MATICS      By  A.  N.  Whitehead 

A.STRONOMY By  A.  R.  Hinks 

PSYCHICAL  RESEARCH   .    .    .    .  By  W.  F.  Barrett 
THE   EVOLUTION   OF   PLANTS  By  D.  H.  Scott 
CRIME   AND   INSANITY  ....   By  C.  A.  Mercier 
MATTER  AND   ENERGY  ....   By  F.  Soddy 

PSYCHOLOGY By  W.  McDougall 

PRINCIPLES    OF    PHYSIOLOGY  By  J.  G.  McKendrick 
THE  MAKING  OF  THE  EARTH  By  J.  W.  Gregory 

ELECTRICITY By  Gisbert  Kapp 

THE  HUMAN  BODY By  A.Keith 

Future  Issues 

CHEMISTRY By  R.  Meldola 

THE  MINERAL  WORLD  ....  By  Sir  T.  H.  Holland 


THE 

ORIGIN  AND  NATURE 

OF  LIFE 


BY 

BENJAMIN  MOORE 

M.A.,    D.SC,    F.R.S. 

JOHNSTON    PROFESSOR    OF    BIO-CHEMISTRY 

UNIVERSITY    OF    LIVERPOOL 


NEW  YORK 

HENRY  HOLT  AND  COMPANY 

LONDON 

WILLIAMS   AND    NORGATE 


CONTENTS 


CHAPTER 

I  Physical  and  Psychical  Evolution 

II  Genesis  of  Electrons  and  Atoms 

III  Chemical  Evolution  in  the  Suns  . 

IV  Chemical  Compounds  on  Earth 
V  Building  Materials  for  Living  Matter 

VI  Evolution  of  Colloids 

VII  The  Origin  of  Life       .         .         • 

VIII  How  Life  Came  to  Earth 

IX  The  Living  Organism  at  Work 

X    Cyclic  Activities  of  Life  :   Waking  and 
Sleeping  :  Fatigue  and  Recuperation 


Bibliography 
Index   •        . 


PAGE 

7 

27 
51 
79 
104 
123 
158 
171 
197 

243 
254 
255 


THE  ORIGIN  AND  NATURE 
OF  LIFE 

CHAPTER   I 

PHYSICAL  AND   PSYCHICAL  EVOLUTION 

Whether  the  human  mind  be  dealing  with 
the  problems  of  some  branch  of  natural 
science,  or  constructing  systems  of  ethics, 
philosophy,  or  religion,  it  is  equally  essential 
to  clothe  its  thoughts  in  language  derived 
from  those  things  in  the  material  world 
which  appeal  to  the  human  senses. 

The  extent  and  accuracy  of  our  knowledge 
of  external  phenomena  increase  all  the  time, 
and  it  is  this  increase  of  knowledge  which 
makes  all  science  progressive. 

True  religion  apart  from  dogma  is  the 
sublimed  essence  of  the  knowledge  of  the 
highest  things  in  the  world,  and  in  itself  is 
never  opposed  to  natural  science  ;  but  when 
there  is  error  in  men's  conceptions  of  religion 
or  of  natural  science,  then  there  may  for  a  time 
appear  to  be  a  conflict.     But  as  time  advances 

D.  H.  HILl  LIBRARY 
North  Carolina  State  Colleg# 


8     ORIGIN  AND  NATURE  OF  LIFE 

and  thought  on  both  sides  becomes  clearer,  it 
is  found  that  both  religion  and  science  stand 
out  as  a  united  whole  purified  by  the  removal 
of  the  dross  and  more  brightly  radiant  in 
intrinsic  beauty  and  loveliness. 

Seventy  years  have  elapsed  since  Macaulay 
made  his  famous  pronouncement  in  his 
remarkable  essay  on  Ranke's  "  History  of 
the  Popes,"  that  neither  natural  theology 
nor  revealed  religion  is  a  progressive  science, 
and  the  advances  in  religious  thought  and 
scientific  knowledge  during  those  seventy 
years  have  alike  refuted  his  position,  and 
shown  that  religion  as  much  as  any  science 
is  progressive  in  its  nature,  and  that  man's 
religious  thought  broadens  with  the  flight 
of  time. 

When  new  scientific  facts  are  suddenly 
thrown  in  amongst  old  pre-conceived  ideas  of 
divinity,  there  may  at  first  appear  discords, 
and  zealous  champions  of  natural  science,  and 
of  religious  knowledge,  fly  to  arms  and 
indulge  in  acrimonious  polemics  ;  but,  as  time 
advances  and  things  that  are  crude  and 
adventitious  are  thrown  away  on  each  side, 
it  is  discovered  that  science  has  added  a  new 
beauty  to  religion,  or  rather  revealed  a  beauty 
that  was  there  all  the  while,  but  concealed 
by  misconception,  or  by  lack  of  knowledge. 


MATTER   AND   MIND  9 

The  presence  of  this  progress  and  organic 
evolution  in  religion,  ethics,  and  social  science, 
cannot  be  doubted  by  any  thoughtful  person 
of  middle  age  who  will  cast  his  mind  back  on 
the  change  in  religious  thought  and  teaching 
during  his  own  life,  and  if  ampler  confirmation 
be  required,  it  may  readily  be  obtained  by 
comparing  a  volume  of  sermons,  or  some  other 
form  of  theology,  written  say  a  hundred  years 
ago  with  a  modern  work.  If  a  similar  appeal 
be  made  in  the  case  of  natural  science  the  like 
result  will  be  obtained,  and  to-day  we  laugh  at 
the  naive  conceptions  of  natural  philosophers 
of  a  century  ago,  just  as  much  as  we  sometimes 
shudder  at  the  religious  ideas  of  their  con- 
temporaries who  invented  theological  dogmas 
which  we  have  now  buried  in  a  merciful 
oblivion. 

But  the  eternal  truths  of  science  and 
religion  were  the  same  one  hundred  years  ago 
as  they  are  to-day  and  as  they  will  be  one 
hundred  years  hence,  both  realms  of  know- 
ledge, as  well  as  our  inborn  desires  to  penetrate 
their  mysteries,  are  a  part  of  the  great  plan  of 
creation,  and  in  their  intrinsic  laws  remain 
the  same  "  yesterday,  to-day  and  forever." 
It  is  our  knowledge  and  powers  of  conception 
that  have  changed  and  not  the  eternal 
verities. 


10    ORIGIN  AND  NATURE  OF  LIFE 

Looked  at  from  this  point  of  view  the 
differences  between  natural  and,  so-called, 
revealed  religion  disappear  and  every  dis- 
covery of  science  becomes  revealed  religion, 
and  the  scientific  discoverer  the  minister  of 
the  Infinite.  Should  such  a  discovery  later 
be  replaced  by  something  higher,  or  receive 
limitations  as  the  result  of  later  discoveries, 
then  it  is  modified  or  disappears  from  revealed 
religion  just  as  much  early  legend  that  was 
purely  mythological  in  religion  has  had  to 
disappear  with  the  advance  of  natural  science, 
although  regarded  by  earlier  theologians  as  an 
intrinsic  part  of  revealed  religion  in  the 
narrower  sense  of  the  word. 

Such  reflections  as  the  above  might  seem 
ill -chosen  in  introducing  a  work  on  natural 
science,  were  it  not  that  this  volume  is  intended 
to  deal  with  a  subject  which  is  supposed 
to  be  shared  by  theologian  and  natural 
philosopher,  because  it  possesses  both  a 
physico-chemical  and  a  psychical  side.  The 
natural  philosopher  is  studying  the  machine 
which  evolves  that  set  of  energy  phenomena 
which  display  the  mind,  and  hence  although 
working  at  a  different  level  may  be  dealing 
with  matters  of  interest  to  the  psychologist 
and  theologian.  It  must  frankly  be  admitted 
on  both  sides  that  this  interpenetration  does 


MATTER   AND    MIND  11 

exist  and  cannot  be  dissolved.  The  worker 
on  the  higher  and  more  difficult  psychical 
aspects  must  pay  attention  to  the  findings 
of  the  bio-chemist  and  physiologist,  for  he 
may  be  quite  certain  that  anything  less 
certainly  proven  at  a  higher  level  which  runs 
counter  to  chemistry  and  physics  will  in  the 
end  be  found  to  be  erroneous.  Similarly,  the 
chemist  on  his  part  must  not  allow  his  vision 
to  be  narrowed,  and  refuse  to  believe  that 
factors  exist  which  do  not  come  within  the 
problem  of  his  science,  so  long  as  they  are 
not  really  impossible  as  a  superstructure  to 
his  basis  when  his  science  and  that  of  the 
psychologist  have  become  more  developed. 
The  incompatible  on  both  sides  must  be 
examined  and  investigated  until  incompatibil- 
ity has  disappeared,  because  it  is  certainly 
due  to  error  or  incomplete  knowledge  on 
either  side,  or  on  both,  but  outside  this 
limitation  each  worker  must  have  perfect 
liberty  to  pursue  his  investigations.  This 
plan  is  the  one  seen  daily  in  operation.  One 
scientific  worker,  taking  certain  things  for 
axiomatic,  is  at  work  at  a  level  to  which  the 
scientists  of  another  group  have  not  yet  built 
up.  The  temple  of  knowledge  is  grand 
enough  in  its  superb  proportions  to  find 
working  room  for  all  of  them,  and  the  work 


12     ORIGIN  AND  NATURE  OF  LIFE 

yields  pleasure  at  its  highest  to  all  the 
artificers. 

It  would  never  have  done  for  the  physiolo- 
gist to  remain  idle  till  the  chemist  had  dis- 
covered the  nature  and  properties  of  all  the 
chemical  constituents  of  the  body,  nor  for  the 
psychologist  to  abandon  the  study  of  the 
mind  until  the  physiologist  had  supplied  him 
with  a  complete  physical  basis  for  his  work  by 
elucidating  the  minute  structure,  relation- 
ships and  simple  reactions  of  the  nervous 
system.  It  would  have  gone  hardly  with  the 
world's  invalids,  as  also  with  the  health  of  the 
whole  community,  if  the  physician  and  sur- 
geon had  waited  for  the  completed  sciences 
of  chemistry,  biology,  physiology  and  psycho- 
logy before  tackling  the  problems  of  disease, 
although  every  year  they  stand  indebted  for 
further  advances  to  discoveries  made  in  these 
cognate  sciences. 

Such  reasoning  extends  right  up  into  the 
highest  regions  of  human  thought  and  activity, 
into  the  study  of  the  so-called  humanities, 
history,  sociology  and  religion.  Each  one  is 
progressive,  all  are  living  and  moving,  dis- 
covery in  one  affects  others,  and  all  must  be 
studied  simultaneously,  each  by  its  own  host  of 
votaries.  Very  often  the  exclusive  study  of 
one  branch  of  knowledge  at  close  quarters 


MATTER   AND    MIND  13 

causes  the  student  to  lose  perspective  and 
deny  the  importance,  or  even  the  existence, 
of  other  knowledge.  Such  a  person  is  merely 
uneducated  or  it  may  be  is  incapable  of 
education  through  some  natural  defect.  He 
resembles  some  one  with  a  lack  of  appreciation 
of  harmony  who  cannot  understand  why 
another  person  enjoys  music,  or  one  who, 
short  of  actual  colour  blindness,  cannot  appre- 
ciate pictures,  or  the  glorious  beauty  of  Nature 
in  scenery,  or  in  the  forms  of  living  plants  or 
animals.  The  assertions  of  such  a  person 
should  not  irritate  the  man  who  has  been 
gifted  with  higher  sense,  he  is  rather  to  be 
pitied,  helped  as  far  as  possible,  and  taught 
like  one  who  is  partially  blind  or  deaf.  It  is 
also  to  be  remembered  that  such  a  defective 
person  in  one  direction  may  be  so  endowed 
as  to  be  a  genius  in  another,  and  that  the  true 
action  of  average  humanity  ought  to  be  to 
accept  his  genius  while  discounting  and  par- 
doning his  eccentricity.  The  world  has  lost 
much  invaluable  service  in  all  realms  of  thought 
and  action,  and  some  of  its  brightest  geniuses 
have  been  outlawed  or  slain  as  martyrs,  simply 
because  of  the  associated  eccentricity  accom- 
panying genius  which  the  average  mortal 
regards  as  madness  or  crime. 

As  an  example  of  the  effects  of  narrow 


14    ORIGIN  AND  NATURE  OF  LIFE 

study  there  may  be  taken  the  statement  that 
the  life-processes  contain  no  problems,  save 
those  of  chemistry  and  physics.  When  this 
statement  is  examined  rigorously  it  will  soon 
be  seen  that  it  cannot  be  passed  off  as  a 
complete  expression  of  all  human  philosophy. 
Our  thoughts  must  obviously  be  something 
different  from  chemistry  and  physics  since 
they  can  live  and  re-awaken  thought  in 
others  centuries  after  our  demise,  but  in 
the  production  and  transference  of  such 
thoughts  between  speaker  and  auditor,  or 
writer  and  reader  the  basis  all  the  time  is 
obviously  physical  and  chemical  change 
or  reaction  in  the  brain,  special  senses,  and 
other  parts  of  the  body.  Each  link  in  the 
chain  may  be  physico-chemical,  but  the  chain 
as  a  whole,  and  its  purpose,  is  something  else. 
As  well,  in  a  concert,  might  it  be  said  that  each 
musical  note  was  physico-chemical  and  that 
the  blending  in  time  and  pitch  were  purely 
physical  factors  which  gave  rise  to  the  pleas- 
ure ;  but  there  is  the  mind  of  the  composer, 
the  performers  and  the  auditors,  and  there  is 
something  which  takes  cognizance  of  the 
whole  effect,  and  to  say  the  very  least  of  it 
the  physicist  and  chemist  have  not  yet  ex- 
plained it,  and  have  proven  nothing  more 
than  that  the  physico-chemical  processes  are 


MATTER   AND   MIND  15 

the  vehicle  of  the  whole  thing,  the  instrument 
upon  which  something  is  played. 

The  higher  the  ascent  that  is  made  in  the 
scale  of  human  thought  and  activity  and  the 
closer  f  pproach  that  is  made  to  those  things, 
which,  in  so  many  civilized  races  in  common 
and  yet  independently,  have  been  regarded 
as  divine  or  sacred,  the  clearer  does  this  dis- 
tinction become. 

It  is  well  known  to  us  now  that  the  love 
of  order  and  beauty  as  we  perceive  it,  is  a 
part  of  all  nature,  and  our  love  of  the  beautiful 
is  part  of  the  evolution  which  was  shaping  and 
forming  beautiful  things  in  creation  long 
before  man  was  there  to  appreciate  them  and 
take  his  part  in  the  scheme  of  creation,  but 
what  is  the  exact  relationship  of  chemistry 
and  physics  to  this  innate  love  of  beauty  and 
science  ?  When  we  know  more  chemistry  and 
physics  we  shall  understand  it  better,  but  it  is 
as  yet  too  early  to  exclude  all  but  chemistry 
and  physics  from  the  scheme  of  our  philosophy. 

The  study  of  our  social  relationships  to  our 
fellow-men  again  furnishes  an  example  of  the 
relationship  of  chemistry  and  physics  to 
psychological  and  religious  problems.  Nearly 
all  social  problems  have  a  material  basis, 
but  the  interconnections  and  the  factors  which 
sum  up  and  urge  us  forward  to  solve  such 


16     ORIGIN  AND  NATURE  OF  LIFE 

problems,  and  in  so  doing  develop  the  highest 
and  noblest  instincts — these  are  something 
more  than  the  purely  physical. 

The  material  substructure  must  be  there  to 
render  thought  possible,  and  as  soon  as  that 
substructure  develops  it  becomes  inhabited  by 
certain  forms  of  energy  which  become  more 
complex  in  their  manifestations  as  the  sub- 
structure evolves.  Structure  and  function 
react  upon  each  other  as  evolution  proceeds, 
and  there  is  throughout  a  continuity,  but  it  is 
questionable  if  anything  is  gained  by  assuming, 
while  our  knowledge  is  still  so  incomplete, 
that  matter  may  not  follow  new  laws  as  it 
becomes  more  complex,  for  new  forms  or 
manifestations  of  energy  may  arise  which  were 
impossible  or  lacking  to  the  simpler  forms  of 
matter.  Care  is  needed  that  in  entering  into 
disputations  as  to  whether  it  is  not  all  chem- 
istry and  physics,  terminology  is  not  becoming 
confused  so  that  the  dispute  is  only  over  terms 
instead  of  over  things. 

A  remarkably  clear  side  light  is  thrown 
upon  the  problem  if,  instead  of  passing  up- 
wards in  complexity  of  structure  of  matter 
towards  life,  consideration  is  given  to  the 
energy  changes  which  occur  when  matter 
becomes  more  simple  in  structure.  This  will 
be  dealt  with  later  in  greater  detail  when 


MATTER   AND    MIND  17 

inorganic  evolution  is  considered,  but  here, 
it  may  be  remarked  that  the  whole  of  the 
wonderful  new  land  discovered  by  radio- 
activity has  revealed  to  us  that  when  matter 
is  radio-active  it  possesses  new  energy  proper- 
ties which  are  not  found  elsewhere.  Radio- 
active particles  which  possess  less  than  one- 
thousandth  part  of  the  mass  of  any  elementary 
atom  previously  known  to  us,  possess  a  rela- 
tively enormous  store  of  a  new  type  of  energy 
with  a  set  of  properties  entirely  its  own, 
yet  bearing  relationships  to  other  well-known 
forms  of  energy,  itself  derivable  from  these 
well-known  forms,  and  re-convertible  back 
again  into  them.  If  matter  in  simpler  forms 
than  the  atoms  to  which  we  have  long  been 
accustomed  possesses  new,  strange  forms  of 
energy,  is  there  any  need  to  shut  our  eyes  to 
the  fact  that  as  matter  increases  in  degree  of 
complexity  and  eventually  becomes  the  basis 
of  life  it  will  begin  to  manifest  new  energy 
properties  and  give  rise  to  energy-transforma- 
tions and  phenomena  such  as  are  never  seen 
in  inorganic  nature  ? 

As  will  be  shown  in  the  development  of 
the  subject  such  energy  manifestations  char- 
acteristic of  life  do  occur  and  form  the  special 
subject  of  study  of  the  bio-chemist  and 
physiologist    just  as  radio-activity  and  the 


18     ORIGIN  AND  NATURE  OF  LIFE 

laws  of  inorganic  chemistry  furnish  a  life- 
study  for  the  chemist  and  physicist.  More- 
over, there  is  no  breach  of  continuity  between 
the  inorganic  and  the  organic,  or  any  need 
for  the  postulation  of  an  abrupt  act  of  creation 
of  the  organic  from  the  inorganic  at  some 
definite  past  moment  in  cosmic  history  which 
has  never  been  repeated. 

There  exists  a  whole  territory  of  approach 
between  the  inorganic  and  the  organic  in 
what  is  known  as  the  chemistry  of  the  col- 
loids, and  it  is  a  most  remarkable  thing  that 
this  great  fact,  which  is  only  now  beginning 
to  be  appreciated,  was  perceived  and  clearly 
set  forth  by  Thomas  Graham,  the  pioneer 
worker  on  the  chemistry  of  the  colloids,  to 
whom  we  owe  the  introduction  of  the  term 
colloid  and  many  master  discoveries  in  this 
most  interesting  zone  of  chemistry  which  now 
claims  hundreds  of  ardent  workers  all  over 
the  world. 

The  study  of  colloids  has  not  only  had 
profound  effects  upon  our  philosophical 
conceptions  of  chemistry ;  it  is  producing 
enormous  changes  in  many  fields  of  industry, 
for  colloids  are  amongst  the  most  important 
of  the  chemical  substances  utilized  by  civi- 
lized man,  and  in  the  future  the  study  of  the 
properties    of    the    colloids    found   in   living 


MATTER   AND    MIND  19 

structures  will  revolutionize  our  knowledge 
of  biology  and  physiology,  and  cause  astound- 
ing advances  in  the  applied  medical  sciences. 

The  mystery  of  life  is  often  spoken  of  as  if  it 
were  the  crowning  mystery  of  all  things,  and 
indeed  it  has  its  wonderful  secrets  like  all  the 
natural  phenomena  of  the  world.  But  the 
riddle  of  the  universe  lies  much  deeper  than 
life.  The  evolution  of  life  from  inorganic 
materials  is  only  one  stage  more  mysterious 
than  the  evolution  of  any  one  form  of  matter 
from  another,  for  in  fact  it  is  of  that  type, 
and  the  new  energy  changes  are  little  more 
startling  than  those  which  occur  at  other  levels 
in  the  chain  of  creation.  The  fundamental 
mystery  lies  in  the  existence  of  those  entities, 
or  things,  which  we  call  matter  and  energy, 
and  in  the  existence  of  the  natural  laws  which 
correlate  them  and  cause  all  those  things  to 
happen  which  the  natural  philosopher  observes 
and  classifies  and  correlates,  but  cannot 
explain  in  one  single  instance. 

The  scientist  has  perceived  through  his 
senses  the  existence  of  certain  things,  and  that 
by  following  certain  laws  a  world  including 
himself  is  evolved.  He  has  proceeded  to 
enunciate  and  work  out  the  simplest  system 
which  will  correlate  all  these  things  ;  and  all 
scientific  work  consists  in  extending  this  sys- 


pf 


20     ORIGIN  AND  NATURE  OF  LIFE 

tern,  filling  gaps  in  it,  and  elucidating  apparent 
exceptions.  All  this  is  of  the  highest  value 
to  him,  and  to  the  higher  processes  of  evolu- 
tion in  which  he  himself  is  a  conscious  factor. 
The  highest  advantage  accruing  to  him  is  the 
study  itself  and  the  means  which  arise 
incidentally  to  the  study  of  enlarging  its 
scope  and  making  new  advances.  Compared 
to  this  higher  pleasure  the  material  advan- 
tages are  but  trumpery,  and  too  often 
act  as  an  enervating  influence  on  the  less 
studious  portion  of  humanity,  or  form  the 
means  of  degrading  and  enslaving  the 
many  millions  who  do  not  possess  enough 
scientific  knowledge  to  arrange  how  to  share 
the  material  benefits  so  that  they  may  be  a 
blessing  to  all  instead  of  a  curse  alike  to  those 
who  possess  too  much  and  those  who  possess 
too  little. 

Despite  these  material  advantages  or  dis- 
advantages to  the  world  at  large  springing 
from  his  work,  the  true  scientific  pioneer, 
whom  we  may  regard  as  we  choose  either  as 
the  genius  or  the  genie  of  higher  evolution,  is 
irresistibly  impelled  by  his  natural  endow- 
ments to  go  on  cataloguing,  and  arranging, 
and  investigating  natural  phenomena,  and  it 
is  well  that  we  should  consider  at  the  outset 
what  are  the  apparent  limitations  of  the  age 


MATTER   AND    MIND  21 

upon  such  labours,  without  attempting  to 
fix  any  impossible  gulf  which  some  superman 
of  future  evolution  may  not  be  able  to  pass 
over. 

The  scientist  after  he  has  collected  a  suffi- 
cient number  of  accurate  observations,  may 
discover  an  existing  law  of  science  which 
enables  him  to  correlate  phenomena,  and  in 
a  secondary  sense  explain  them ;  but  he 
never  discovers  the  primary  cause  that  has 
set  his  law  in  existence.  His  observations 
have  taught  him  that  something  which  he 
names  matter  or  material  exists  in  many  var- 
ious forms,  deeper  study  has  shown  him  the 
relationships  of  these  forms  to  one  another 
and  enabled  him  to  reduce  the  number  of 
primary  forms  of  matter  to  a  small  set,  which 
for  the  time  he  called  chemical  elements, 
and  from  which  he  has  been  able  by  appro- 
priate unions  to  construct  hundreds  of  thous- 
ands of  derived  forms.  Even  now  he  stands 
on  the  verge  of  the  discovery  that  all  his 
elements  are  derived  from  one  form  of  stuff 
only,  which  may  not  be  matter  itself,  but 
when  tenanted  by  something  which  he  has 
recognised  and  named  as  energy  becomes 
converted  into  forms  of  matter  leading  up  to 
those  elements  which  he  first  unearthed. 
But  as  to  why  all  these  things  happen,  or 


22     ORIGIN  AND  NATURE  OF  LIFE 

exist,  he  possesses  as  yet  no  knowledge.  It  is 
just  here  at  this  fundamental  point  that 
science  and  religion  meet  in  the  minds  of 
most  men  who  have  thought  deeply  enough 
about  the  problem,  and  here,  since  farther 
penetration  is  as  yet  impossible,  it  is  open  to 
each  thinker  either  to  declare  he  must  leave 
the  problem  so,  or  to  call  in  something  in  the 
nature  of  an  infinite  intelligence  which  sur- 
passes himself  in  that  it  possesses  the  power 
of  inducing  these  fundamental  properties 
and  activities  upon  matter  throughout  all 
space  and  time. 

The  first  position  never  has  satisfied,  and 
as  evolution  advances  will  still  less  satisfy 
the  mind,  the  second  position  at  all  ages  in 
the  world's  history  of  which  we  possess  any 
record  has  led  to  the  evolution  of  systems  of 
religion.  Imagination  is  as  fundamentally 
important  for  a  student  of  natural  science 
as  for  a  poet  or  a  devotee  of  a  religious  belief. 
It  is  by  the  use  of  the  imagination  that  science 
is  led  on  from  discovery  to  discovery,  but 
the  essential  difference  lies  in  this,  that  in  the 
legitimate  domain  of  natural  science  the  work 
of  the  imagination  must  be  proven  by  the  test 
of  experiment,  which  alone  gives  the  true 
clue  towards  the  reading  of  the  romance  of 
science  which  lies  there,  written  we  know  not 


MATTER    AND    MIND  23 

how,  for  translation  by  us.  In  the  psychical 
world  there  exists  no  such  touchstone  of 
experiment,  and  there  does  exist  the  funda- 
mental difficulty  of  building  up  a  system  of 
thought  on  anything  else  than  a  materialistic 
basis,  so  that  in  the  last  resort  the  theologian 
becomes  just  as  materialistic  as  the  veriest  me- 
chanician. It  is  important  for  the  materialist 
to  realize  that  his  methods  of  experimentation 
cannot  be  extended  to  touch  or  test  things 
of  a  purely  psychical  nature,  and  it  is  equally 
important  for  the  psychologist  to  remember 
that  he  has  only  so  far  been  dealing  with 
materialistic  models,  and  studying  the  sub- 
structure in  which  mental  acts  occur.  Neither 
set  of  philosophers,  whatever  their  beliefs 
may  be,  can  prove  or  disprove  anything  as  to 
the  existence  of  mind  apart  from  matter, 
or  what  are  the  subtle  relationships  of  mind 
and  matter. 

The  ordered  beauty  of  the  world  of  Nature 
suggests  an  infinite  intelligence  with  powers 
of  action  such  as  no  man  or  other  creature 
possesses,  and  evolution  which  was  so  hotly 
contested  by  the  theologians  of  a  generation 
ago,  suggests  the  beautiful  conception  of 
continued  action,  but  when  man  commences 
to  speculate  as  to  the  nature  of  this  intelli- 
gence   which    rules    the    universe,    however 


24     ORIGIN  AND  NATURE  OF  LIFE 

much  of  a  theologian  he  may  be,  he  is  driven 
back  upon  materialistic  models,  and  his 
deity  cannot  rise  above  a  perfected  superman. 
In  the  present  state  of  human  evolution,  even 
revelation  from  the  deity  could  not  conceivably 
take  any  other  form  than  this,  for  man  with 
such  senses  and  experiences  as  he  has  been 
provided  with,  could  not  understand  anything 
else. 

Science  can  readily  strip  away  from  any 
earlier  system  of  religion,  mythological 
accounts  of  creation  which  represent  the 
state  of  natural  knowledge  when  the  system 
was  growing,  and  can  disprove  or  reject 
accounts  of  natural  phenomena  which  are 
now  known  clearly  to  be  errors,  but  when 
this  has  all  been  done  the  real  kernel  still 
remains  in  any  religious  system  worthy  of 
the  name.  Man  is  still  left  venerating  the 
great  causes  of  creation,  and  worshipping 
at  the  shrine  of  an  infinite  and  all-powerful 
creator.  Nor  is  it  any  bar  to  this  worship 
that  he  possesses  no  rigorous  proof  nor  exact 
knowledge  in  terms  of  material  things.  The 
mysticism  only  stimulates  devotion,  and  urges 
him  onwards  towards  higher  realization  of 
divinity  and  idealization  of  all  that  is  highest 
in  the  deity  that  he  personifies  and  worships. 

To  such  a  worshipper  every  scientific  ad- 


MATTER   AND    MIND  25 

vance  brings  only  a  more  beautiful  apprecia- 
tion of  the  divine  in  nature,  and  he  strains 
upwards  towards  it  in  his  own  life,  and  is 
impelled  by  his  religion  to  a  nobility  of  life 
and  character,  which  could  scarcely  arise  ia 
any  other  way. 

If  this  attribute  of  mind,  to  recognize  some- 
thing as  the  highest  in  the  whole  range  of 
consciousness  which  compels  the  mind  towards 
its  highest  efforts,  exists  in  millions  of  the 
most  highly  developed  of  mankind  there  must 
be  some  cause  for  it  other  than  ignorance. 
Surely  it  is  part  of  mental  evolution  towards 
the  highest — an  intensification  of  that  same 
process  which  led  creation  up  from  undiffer- 
entiated matter  through  the  long  course  of 
organic  evolution  to  man.  Man  has  now 
become  aware  of  this  organic  evolution,  and 
there  is  a  consciousness  developing  in  regard 
to  it  and  making  for  social  progress,  which  is 
rapidly  becoming  the  latest  and  highest  deve- 
lopment of  religion.  Environment  acting  as 
a  directing  and  selecting  power  upon  mutable 
forms  of  matter,  and  lasting  through  long 
epochs  of  time  finally  brought  man  upon 
the  earth,  purely  material  environment  cannot 
raise  him  higher,  but  in  religion  in  the  true 
sense  of  the  word,  increased  and  intensified 
by  a  study  of  the  mind,  and  of  our  relation- 


26     ORIGIN  AND  NATURE  OF  LIFE 

ship  and  duties  towards  other  minds,  we 
see  that  factor  in  our  environment  which 
will  lead  us  on  to  higher  things. 

The  fact  that  the  creature  actually  in  pro- 
cess of  evolution  has  gained  consciousness  of 
his  own  evolution  will  give  a  definite  purpose 
to  his  whole  social  system  as  a  community, 
and  will  enormously  increase  the  velocity  in 
future  generations  of  the  process  of  evolution. 

Having  thus  far  attempted  to  define  the 
relationships  of  the  physico-chemical  and 
the  more  purely  psychical  processes  of  living 
things,  the  remainder  of  this  volume  will  chiefly 
be  devoted  to  describing  the  chain  of  evolution 
whereby  the  organic  originates  from  the 
inorganic,  and  to  the  nature  of  the  energy 
exchanges  which  occur  in  the  living  organism 
after  it  has  evolved. 

The  value  of  imagination  to  the  scientist 
has  been  mentioned  above,  and  at  the  outset 
it  was  pointed  out  that  in  imagining  a  scienti- 
fic system  to  carry  him  forward  from  known 
facts  to  fresh  discoveries,  the  scientist  equally 
with  the  theologian  was  compelled  to  build 
upon  materialistic  models.  It  follows  there- 
from that  the  orthodox  scientific  beliefs  of  one 
generation  become,  in  part  at  least,  the  scien- 
tific myths  of  a  succeeding  one,  and  that 
science  just  as  much  as  religion  possesses  its 


ELECTRONS   AND   ATOMS         27 

dead  mythology.  It  by  no  means  follows 
that  these  myths,  of  science  and  religion,  did 
not  serve  a  useful  purpose  in  those  days  when 
they  were  living  and  powerful  beliefs,  but, 
when  new  knowledge,  power  and  methods 
arise,  they  must  be  cast  on  one  side,  and 
replaced  by  better  machinery  to  lead  to  new 
revelations.  They  are  the  scaffolding  of  the 
structure  in  course  of  erection,  and  not  an 
intrinsic  part  or  any  permanent  adornment 
of  it. 


CHAPTER   II 

GENESIS    OF   ELECTRONS   AND   ATOMS 

At  the  present  moment  in  scientific  history, 
as  a  result  of  a  rapid  and  brilliant  series  of 
experimental  discoveries  which  have  taken 
place  during  the  last  fifteen  years,  we  stand 
face  to  face  with  necessary  changes  in  our 
scientific  theories,  concerning  the  nature  of 
two  things,  matter  and  energy,  regarded  by 
our  predecessors  as  definitely  settled  founda- 
tions of  all  science. 

It  is  not  perhaps  too  much  to  say  that 
twenty  years  ago  there  had  developed  a  cast- 
iron  belief  that  matter  and  energy,  and  these 


28     ORIGIN  AND  NATURE  OF  LIFE 

alone,  were  the  two  fundamental  entities  of 
the  physical  world,  and  that  each  was  eternal, 
unalterable,  and  had  existed  in  fixed  amount 
from  the  beginning  of  days,  uncreatable  and 
indestructible. 

This  fixed  belief  led  to  many  great  discov- 
eries, although  there  is  little  question  that  it 
also  delayed  and  inhibited  others  by  setting 
up  an  unwarrantable  boundary  to  thought. 
The  fundamental  experimental  discoveries 
upon  which  these  laws  of  the  conservation  of 
matter  and  conservation  of  energy  were  based, 
still  remain  intact,  and  in  certain  directions 
potent  to  lead  to  discovery.  There  is  no  need 
to  abandon  them  entirely,  but  recent  experi- 
ments have  shown  that  they  must  be  modified, 
and  given  their  limitations,  and  this  defect 
in  the  scientific  idols,  having  been  discovered, 
it  has  become  permissible  to  examine  them 
critically,  without  being  guilty  of  sacrilege, 
to  discover  if  perchance  any  other  part  than 
their  feet  is  made  of  clay. 

To  put  the  case  in  as  simple  and  non-tech- 
nical language  as  possible,  matter  represents 
the  stuff  or  structure  of  the  universe,  as  obvious 
to  our  senses  unaided,  or  aided  by  artificial 
means,  and  energy  is  the  activity  (or  the  power 
to  develop  activity  due  to  relative  position) 
of  the  component  parts  of  the  stuff  or  matter. 


ELECTRONS    AND    ATOMS         29 

The  doctrine  of  the  conservation  of  matter 
teaches  that  the  sum  total  of  material,  or 
matter,  is  constant  or  fixed  however  it  chanced 
to  be  or  come  there  originally,  and  that  matter 
cannot  be  created  or  destroyed. 

The  doctrine  of  the  conservation  of  energy 
teaches  the  same  for  the  activities,  or  poten- 
tial activities  of  matter,  namely,  that  the 
sum  total  of  the  various  manifestations  of 
energy  is  a  constant.  Energy  may  pass  from 
one  form  to  another,  and  the  quantity  present 
in  any  given  form  may  and  does  vary,  for  it  is 
the  passage  from  one  form  to  another,  which 
constitutes  all  natural  phenomena ;  but  there 
is  no  manufacture  or  destruction  of  energy, 
there  is  the  same  quantity  of  energy  in  the 
universe,  as  was  in  the  beginning,  and  shall 
be  for  ever. 

These  two  great  tenets  are  fundamental  in 
the  orthodox  faith  of  the  scientific  world  of 
our  day.  Let  us  for  the  moment  be  daring 
sceptics  and  examine  them. 

In  the  first  place  the  acceptance  of  these 
doctrines  as  absolutely  settled,  places  a  limit 
on  our  knowledge  both  of  the  past  and  of 
the  future.  As  regards  the  past,  it  becomes 
agreed  that  no  discovery  is  possible  of  how 
matter  originated,  or  activity  in  matter  came 
to  exist,  and  in  respect  to  the  future,  it  is 


30     ORIGIN  AND  NATURE  OF  LIFE 

admitted  that  all  experimentation  directed 
towards  production  or  destruction  of  either 
matter  or  energy  must  prove  in  vain.  The 
only  reason  for  setting  such  limitations  to 
the  knowable  is  that  under  the  conditions  of 
action  which  at  present  we  know,  production 
or  destruction  of  matter  or  energy  does  not 
occur.  If  such  a  position  had  been  accepted 
in  regard  to  earlier  scientific  theories,  we 
should  not  now  know  many  important  things 
which  have  been  added  to  the  common  store  of 
knowledge.  The  acceptance  of  a  completed  act 
of  creation  would  have  precluded,  for  example, 
our  present  knowledge  of  organic  evolution, 
and  the  belief  in  fixed  quantities  of  energy 
and  matter  equally  involves  a  non-progressive 
act  of  creation  at  some  fixed  time  in  the  past. 
The  placing  of  the  creative  act  in  the  more 
remote  past,  or  in  a  fictitious  eternity  even, 
does  not  solve  the  problem. 

The  doctrine  is  precisely  similar  to  the  bio- 
logical doctrine  usually  expressed  by  the 
phrase  of  Harvey,  "  Omne  vivum  e  vivo  " 
(all  life  from  life),  which  closes  the  door  to  all 
attempts  to  solve  our  special  quest  in  this  book 
by  the  dictum  that  life  only  can  come  from 
life,  that  it  never  can  arise  afresh,  and  so  its 
first  origin  lies  shrouded  in  the  unknowable 
past. 


ELECTRONS   AND   ATOMS         31 

As  a  matter  of  fact,  our  experimental  obser- 
vations only  amount  to  this,  that  in  the 
ordinary  and  common  interactions  of  matter 
and  energy  with  which  physicist  and  biologist 
have  hitherto  dealt,  these  laws  hold,  but  we 
must  not  allow  our  naturally  great  respect 
for  them  to  close  our  eyes  to  the  fact  that 
outside  these  limits,  in  types  of  reaction  which 
are  just  beginning  to  dawn  upon  us,  these 
laws,  while  still  holding  in  a  manner,  may  be 
so  varied  as  to  give  room  for  the  inception  of 
both  inorganic  and  organic  evolution. 

By  expenditure  of  energy  in  formation  of 
matter  from  something  less  complex  than 
matter,  or  by  the  setting  free  of  energy  at  a 
high  potential  (or  power)  due  to  destruction 
of  matter,  the  problem  of  creation  may  be 
reducible  to  simpler  terms.  Experimental 
evidence  to  the  exclusion  of  such  a  view  does 
not  exist,  and  traces  of  evidence  are  lately 
beginning  to  come  into  view,  which  are  highly 
suggestive  of  continuous  present-day  creation 
of  matter  at  the  inorganic  level,  and  of  creation 
of  life  from  inorganic  materials  at  the  organic 
level. 

Again,  by  an  extension  of  the  doctrine  of  the 
conservation  of  matter,  it  was,  until  quite 
recently,  held  that  there  existed  a  definite 
number  of  primary  forms  of  matter  amounting 


32     ORIGIN  AND  NATURE  OF  LIFE 

to  about  eighty  in  all,  which  were,  and  are, 
called  the  chemical  elements.  These  forms 
could  not  be  resolved  into  anything  simpler 
by  known  chemical  reactions,  and  for  this 
reason,  indeed,  were  called  elements,  and  by 
combinations  of  these  amongst  one  another, 
all  chemical  compounds  were  formed.  The 
amount  of  each  chemical  element  was  fixed 
and  inviolable,  and  that  same  amount  always 
had  existed  in  the  universe  and  always  would 
exist.  The  evidence  for  this  view  was  just  as 
good,  and  no  better,  than  that  of  which  we 
stand  possessed  for  the  doctrine  of  conserva- 
tion of  matter  as  a  whole,  namely,  that  how- 
ever the  element  might  be  transformed  and 
disappear  into  chemical  combination,  by  the 
application  of  appropriate  chemical  means 
exactly  that  amount  of  it  was  recoverable 
again.  In  all  chemical  reactions  not  only  did 
the  total  masses,  as  measured  by  weighing 
the  reacting  substances,  remain  constant 
so  demonstrating  the  law  of  conservation  of 
matter,  the  total  mass  of  each  element  also 
remained  constant  so  demonstrating  the  law 
of  conservation  of  the  elements. 

But  it  has  recently  been  shown  experiment- 
ally that  matter,  which  by  all  criteria  must  be 
regarded  as  elemental,  in  the  chemical  sense, 
is  in  certain  cases  so  endowed  with  peculiar 


ELECTRONS   AND   ATOMS         33 

energy  properties  that  it  is  slowly  breaking 
down  into  entirely  different  elements,  the  pro- 
cess being  so  slow  that  centuries  of  time  are 
required  for  any  appreciable  breakdown.  At 
the  same  time  enormous  quantities  of  energy 
are  set  free.  Here  from  a  chemical  element, 
new  chemical  elements  are  being  formed,  and 
from  a  chemical  element,  energy  in  immense 
stores  is  being  set  free. 

The  old  doctrine  has  had  to  give  place  as 
a  result,  and  in  its  stead  we  now  believe  that 
each  chemical  element  represents  a  more  or 
less  stable  position  in  the  charging  of  matter 
with  energy.  *  Those  elements  whicn  are 
called  radio-active  and  are  continually  break- 
ing-down as  described  above  are  unstable, 
and  break  down  spontaneously,  while  other 
elements  are  so  stably  related  to  their  energy 
content  that  no  means  that  we  at  present 
know  how  to  apply  are  capable  of  disrupting 
them. 

If  these  things  happen  the  view  becomes 
opened  that  by  energy  discharge  the  most 
primal  matter  may  possibly  be  thrown  into 
something  which  is  not  matter,  in  the  usual 
sense  of  the  word,  and  lacks  those  criteria  by 
which  we  appreciate  matter,  and  if  this  be 
possible  then  by  attaching  energy  to  this 
precursor  of  matter,  it  becomes  possible  to 


34     ORIGIN  AND  NATURE  OF  LIFE 

create  matter.     Thus  the  position  is  arrived 
at  that  instead  of  matter  and  energy  being 
fixed  in  amount,  and  always  conserved,  they 
are  mutually  convertible  into  each  other,  as 
soon  as  we  have  discovered  the  appropriate 
mechanisms  for  the  purpose- 
Again,  energy  is  usually  divided  into  two 
main  varieties,  each  of  which  possesses  several 
forms,    these    varieties    are    termed    kinetic 
energy  and  potential  energy.     Kinetic  energy 
is  energy  due  to  motion,  either  of  a  large  body 
as  a  whole,  or  of  the  atoms  or  molecules,  which 
form    the    minute    mechanically    indivisible 
portions    of    matter,   while    potential  energy 
is  energy  due  to  the  position  of   portions  of 
matter  in  relationship  to  one  another,   and 
here  again  the  matter  may  be  in  larger  masses, 
or  may  consist  of  molecules  or  atoms.     Ex- 
amples of  kinetic  energy  are  such  as  (a)  large 
bodies  in  motion  ;     (b)  heat ;    (c)  light ;    (d) 
electricity ;     (e)   radiations   of   many   kinds ; 
(/)  the  molecular  motions  of  a  gas,  liquid,  or 
solid ;     and   (g)   the   motions   of   constituent 
atoms  of  a  molecule  in  relationship  to  one 
another.     As  examples  of  potential  energy  (in 
which  motion  does  not  come  in)  there  may  be 
quoted   (a)  bodies  raised  above  the  earth's 
surface,  either  solid,  or  fluid,  like  water  in  a  re- 
servoir, or  gaseous,  like  barometric  differences 


ELECTRONS    AND   ATOMS         35 

in  pressure  ;  (b)  magnetic  bodies  at  rest  near 
a  magnet ;  (c)  a  coiled  spring ;  (d)  chemical 
energy  due  to  juxtaposition  of  molecules  or 
atoms,  such  as  is  typically  seen  in  a  high 
explosive,  but  all  chemical  substances  possess 
such  potential  energy  ;  (d)  the  heat  which 
disappears  without  change  of  temperature 
when  a  solid  turns  into  liquid,  or  a  liquid 
into  gas,  as  in  the  formation  of  water  from 
ice  or  steam  from  water,  this  is  called  "  latent 
heat,"  but  is  really  not  heat  at  all ;  (e)  surface 
tension,  such  as  is  seen  in  a  soap-bubble,  or 
at  any  interface  at  rest  between  two  dissimilar 
forms  of  matter. 

These  two  lists  are  not  exhaustive  but  are 
intended  to  show  two  things,  first,  the  large 
number  of  discrete  forms  of  energy  which 
exist,  each  with  a  set  of  natural  phenomena 
of  its  own,  and,  secondly,  how  completely 
different  the  first  set  of  forms  of  energy 
termed  kinetic  are  from  the  members  of  the 
second  or  potential  type.  The  first  are  forms 
of  activity,  the  second,  forms  of  passivity, 
but  a  definite  measured  amount  may  pass 
from  any  one  form  to  another,  and  in  the 
exchange  there  is  never  any  gain  or  loss  in 
amount,  but  always  an  exact  balance.  One 
passive  form  cannot  pass  into  another  passive 
form  without  intermediately  passing  through 


36     ORIGIN  AND  NATURE  OF  LIFE 

an  active  form,  and  although  it  might  seem  pos- 
sible for  one  active  form  to  pass  into  another 
active  form  without  the  intermediation  of  a 
passive  form,  as  a  matter  of  fact,  in  nature, 
this  rarely  or  never  occurs.  Some  intermediate 
change  in  position  of  atoms,  molecules  or  large 
masses  toward  each  other  is  always  involved, 
which  means  a  temporary  development  of 
latent  or  positional  energy.  An  energy  trans- 
formation involving  two  types  of  energy  only, 
is  unknown,  and  usually,  intermediately  at 
any  rate,  many  types  are  produced  in  any 
reaction. 

If  regard  be  paid  to  the  nature  of  the  forms 
termed  potential  energy  it  becomes  obvious 
that  they  are  not  really  forms  of  energy  at  all, 
but  only  potentialities  for  the  development 
of  energy.  The  water  in  a  reservoir  as  a  still 
mass  does  not  really  possess  energy,  it  only 
acquires  energy  as  it  runs  down  hill,  and  it 
is  only  confused  thinking  which  has  led  to  the 
term  potential  energy.  It  would  be  very 
much  clearer  to  recognize  that  there  are  two 
qualities,  energia  and  potentia,  and  that  it  is 
the  sum  of  these  which  is  constant  or  con- 
served. When  this  has  been  done  it  becomes 
discernible  that  all  forms  of  matter,  whether 
elements  or  compounds,  may  be  various  forms 
of  potentia,  in  forming  which  energia  may 


ELECTRONS   AND   ATOMS         37 

disappear,  and  in  disruption  (as  in  radio- 
activity or  in  electron  formation)  energia  may 
reappear.  As  the  result  of  this  the  real  con- 
servation law  becomes  the  constancy  of  energia 
plus  potentia. 

But  if  there  is  movement  something  must 
be  moving,  a  simple  fact  which  appears  to 
have  been  forgotten  by  some  philosophers 
who  have  attempted  to  get  rid  of  matter 
altogether  by  stating  that  it  is  only  vortex 
motion.  Something  must  move  in  the  vortices 
or,  in  other  words,  there  must  be  some 
precursor  of  matter  which  is  converted  into 
matter  when  it  becomes  inhabited  by  energy. 

Such  a  precursor  may  well  be  the  ether,  or 
aether,  which  has  had  to  be  postulated  to 
account  for  the  transmissions  of  energy  which 
occur  through  vacua,  such  as  a  vacuum  bulb 
carrying  electric  radiations  and  radio-active 
discharges  and  radiant  heat  and  light,  or,  the 
interstellar  spaces  such  as  that  between  the 
sun  and  earth  which  carries  the  enormous 
flood  of  energy  as  light  and  heat  to  -supply 
nearly  all  our  sources  of  terrestrial  energy. 

If  it  be  supposed  that  this  ether  is  lacking 
entirely  in  the  properties  of  mass,  it  is  difficult 
to  see  in  what  terms  a  given  quantity  of 
energy  in  transit  through  it  can  be  expressed, 
and  a  conception  is  created  of  energy  entirely 


38     ORIGIN  AND  NATURE  OF  LIFE 

disembodied,  so  to  speak,  from  matter,  which 
is  just  as  difficult  a  conception  as  a  disem- 
bodied spirit,  or  a  soul  away  from  its 
body. 

In  what  way,  then,  it  may  be  asked,  does 
ether  differ  from  ordinary  matter  ?  Recently, 
it  has  been  discovered  that  the  particles, 
or  electrons,  discharged  from  the  negative 
pole  or  cathode  of  an  X-ray  bulb,  or  the 
particles  thrown  off  almost  with  the  velocity 
of  light  from  radium  are  so  minute  that  they 
possess  less  than  a  thousandth  part  of  the 
mass  of  a  hydrogen  atom,  which  disposes  once 
and  for  all  of  the  supposition  that  the  chemical 
atoms  are  ultimate  divisions  of  matter,  and 
suggests  that  atoms  are  built  up  of  electrons. 
Now,  rf  it  be  supposed  that  ether  is  either 
non-particulate  or  made  up  of  particles  of  an 
infinitely  lower  size  than  electrons  and  devoid 
of  energy,  and  that  the  electron  is  the  first 
stage  in  the  building  up  of  matter,  a  hypo- 
thesis is  supplied  on  the  simplest  basis  yet 
attained  for  placing  in  one  long  chain  of 
continuity  both  inorganic  and  organic  evolu- 
tion, and  also  for  the  inclusion  of  many  out- 
standing facts  of  the  new  science  of  radio- 
activity. Also,  the  reason  for  one  interesting 
fact  regarding  energy  transmission  by  the 
ether  becomes  obvious,  and  that  is  that  all 


ELECTRONS   AND    ATOMS         39 

wave-motions  are  transmitted  by  it  with  the 
same  velocity  as  that  of  light. 

Given  a  highly  enough  concentrated  source 
of  energy,  it  is  readily  seen  that  those  forms 
of  matter  of  lowest  atomic  weight  may  be 
formed  out  of  the  ether,  energy  disappearing 
as  kinetic  energy  and  appearing  as  potential 
energy,  or  potentia  of  the  atom. 

Astronomical  physics  teaches  us  that  just 
such  elements  are  to  be  observed  in  the 
hottest  suns  and  in  gaseous  nebulae,  and  it 
may  well  be  that  here  we  see  to-day  matter 
being  created,  and  a  varying  balance  estab- 
lished between  energia  and  potentia,  which 
may,  through  the  long  chain  of  events  of 
increasing  chemical  complexity,  followed  later 
by  organic  complexity  of  living  organisms, 
lead  to  an  inhabited  world. 

It  is  to  Greek  philosophy  that  science  owes 
the  conception  of  matter  being  indivisible 
below  certain  limits,  an  idea  which,  at  a 
certain  stage  of  the  development  of  modern 
chemistry,  led  to  so  many  brilliant  experi- 
mental discoveries.  It  was,  however,  the 
English  chemist,  Dalton,  who  gave  the 
ancient  philosophical  speculations  a  sound 
foundation  of  realized  fact  upon  which  the 
enormous  superstructure  of  chemistry,  as  it 
is  known  to-day,  has  since  been  built  up. 


40     ORIGIN  AND  NATURE  OF  LIFE 

This  foundation  is  none  the  less  firm  because 
it  is  now  realized  that  these  indivisible  atoms 
uncreatable  and  indestructible,  which  Newton 
supposed  to  be  turned  out  completely  formed 
by  the  Creator  in  the  beginning  of  things, 
are  themselves  composed  of  thousands  of 
smaller  particles.  It  is  only  necessary  for 
the  atomic  basis  to  our  chemistry  to  realize 
that  the  atom,  just  like  the  chemical  molecule 
at  a  different  stage,  or  the  fixed  organic 
species  of  the  biologist,  is  a  point  of  stable 
equilibrium  in  upward  evolution.  Between 
each  two  such  points  there  lies  a  region  of 
unstable  equilibrium,  and  as  matter  becomes 
more  charged  with  energy,  surgings  and 
transformations  occur,  and  in  the  greater 
number  of  cases  when  the  cycle  is  complete, 
the  matter  drops  back  again  to  its  stable 
point.  But  occasionally  when  a  supply  of 
energy  at  high-potential,  or  concentration, 
is  available,  there  is  a  huge  wave  of  uplifting 
which  carries  the  matter  involved  over  a  hill 
crest  into  a  higher  hollow  of  stable  equilibrium, 
and  a  new  type  of  matter  becomes  evolved 
at  the  expense  of  kinetic  energy  passing 
over  into  latent  energy  or  potentia.  The 
process  may  be  reversed,  of  course,  and  here, 
matter  at  a  higher  elemental  level  may  be 
decomposed,  setting  free  energy,  as  in  radio- 


ELECTRONS   AND   ATOMS         41 

active  decomposition.  The  Daltonian  atom  is 
thus  only  stable  and  indivisible  within  certain 
limits  of  experimentation. 

As  the  atomic  weight  of  the  atom,  in 
Dalton's  sense,  goes  on  increasing,  its  content 
of  energy  per  unit  amount  of  matter  is  heaped 
up,  and  a  limit  of  atomic  stability  is  reached 
as  the  atomic  weight  increases.  This  is 
shown  by  the  fact  that  uranium  and  radium, 
those  elements  which  show  spontaneous 
disruption,  are  also  those  with  the  highest 
atomic  weights,  as  well  as  by  the  converse 
observation,  that  in  those  situations  where 
chemical  atoms  are  probably  being  created 
by  high  tension  energy,  it  is  those  elements 
with  low  atomic  weights  such  as  hydrogen, 
and  helium,  which  are  present  in  largest 
amounts,  as  shown  by  stellar  spectroscopy. 

It  is  also  a  curious  fact  that  there  appear 
to  be  a  series  of  intervals  or  levels  of  stable 
equilibrium  in  the  building  up  of  the  elements, 
bearing  a  superficial  analogy  to  musical 
octaves.  With  approximately  equal  additions 
in  the  atomic  weight,  there  are  recurrences 
of  the  same  chemical  properties  in  the  elements 
so  that  the  majority  of  the  known  elements 
can  be  arranged  in  groups  or  periods  according 
to  what  is  known  as  the  periodic  law.  So 
completely  does  this  law  run  through  the 


42     ORIGIN  AND  NATURE  OF  LIFE 

whole  scale  of  the  elements  that  it  has  been 
the  means  of  discovering  many  previously 
unknown  members.  The  properties  and  gene- 
ral characteristics  of  a  missing  element  have 
even  been  fairly  well  described  some  years 
before  its  actual  discovery,  much  as  a  biologist 
might  describe  a  necessary  missing  species 
in  a  biological  group  of  living  creatures. 
As  a  result,  the  atomic  weights  of  closely 
related  members  of  a  chemical  family  do  not 
lie  close  together  ;  the  relative  atomic  weights 
of  the  elements,  fluorine  and  iodine,  for 
example,  are  as  19  to  127,  yet  these  belong 
to  the  same  natural  group,  and  intermediately 
are  found  chlorine  at  about  35  and  bromine 
at  87.  The  interesting  point  is,  that  between 
the  level  of  19  and  35,  in  the  value  of  the 
relative  weights  of  the  atoms,  the  chemical 
properties  of  the  intermediately  occurring 
elements  have  run  through  the  whole  gamut 
of  all  the  chemical  families  which  differ  most 
widely  in  chemical  properties,  but  at  35  the 
atomic  circle  has  been  completed,  so  to  speak, 
a  kind  of  octave  has  occurred,  and  a  higher 
member  of  the  original  family  has  been 
evolved.  Space  does  not  allow  us  to  go  into 
this  interesting  law  more  fully  here,  for 
information  upon  it,  as  also  upon  inorganic 
evolution  and  the  constitution  of  matter  and 


ELECTRONS   AND   ATOMS         43 

energy,  reference  may  be  made  to  the  volume 
in  this  library  entitled  "  Matter  and  Energy," 
by  Soddy. 

These  periodic  returns  to  similar  properties 
indicate  rhythmically  recurring  points  of 
stability  in  atomic  evolution.  In  each  series 
forming  a  chemical  family,  instability  mounts 
up  and  the  power  of  reactivity  varies.  The 
members  of  a  group  as  a  whole  may  be  more 
stable  than  those  of  the  group  above  them 
possessing  molecular  weights  a  unit  or  two 
higher  for  each  corresponding  member,  but  at 
length  a  point  is  reached  in  each  group  where 
instability  prevails,  and  no  higher  member 
is  found.  Evolution  has  reached  the  highest 
limit  to  which  the  stability  of  the  atom  will 
carry  it,  and  the  tale  of  evolution  is  then 
taken  up  by  the  chemical  compound,  until 
this  in  turn  loses  its  efficiency,  and  the  next 
stage,  namely,  that  of  the  colloid,  arises. 

Although  it  may  only  be  a  superficial 
analogy,  all  this  bears  a  curious  resemblance 
to  the  events  which  occur  quite  at  the  other 
end  of  the  scheme  of  molecular  architecture. 
It  will  be  shown  later  that  the  unit  of  living 
organisms,  called  the  cell,  consists  of  large 
groups  of  chemical  molecules,  built  up  into  a 
delicately  balanced  mechanism  upon  which 
energy  types  from  the  environment  play,  in 


44     ORIGIN  AND  NATURE  OF  LIFE 

a  loose  or  labile  equilibrium  of  periodic 
building  up  and  breaking  down  in  rhythmic 
flow  all  through  life.  Now,  as  this  living  cell 
grows  in  size  there  appears  to  develop  a  higher 
potential,  or  pressure  of  energy,  of  its  own 
peculiar  type,  which  renders  the  cell  unstable 
also,  and  by  the  establishment  of  what  are 
known  as  dynamic  centres,  a  play  of  energy 
transformations  starts,  causing  the  cell  to 
divide  and  give  rise  to  two  daughter  cells, 
which  are  at  first  stable  in  balanced  equili- 
brium, and  only  by  growth  and  accumulation 
of  energy-pressure  later  reach  a  stage  at  which 
they,  too,  become  unstable  and  again  divide. 
Also,  in  a  complex  many-celled  organism, 
there  are  groups  of  cells  much  like  the  periodic 
groups  of  the  chemical  elements.  Some  cells 
are  permanent  or  stable,  and  do  not  divide 
throughout  life,  at  any  rate  after  the  full 
size  of  the  individual  of  which  they  form  a 
constituent  part  has  been  attained.  Their 
period  of  stability  is  the  same  as  that  of  the 
whole  animal.  Other  cells  are  most  unstable, 
with  energy  content  reaching  a  maximum 
and  leading  to  cell-division  at  frequent 
intervals  ;  such  cells  as  these  are  many  times 
formed,  and  perish,  in  the  life  of  the  animal. 
Incidentally  it  may  be  pointed  out  that 
it  is  this  varying  stability  which  determines 


ELECTRONS   AND   ATOMS         45 

the  cycle  of  life  of  the  individual.  There  is 
a  popular  fallacy  in  lay  minds  that  the  whole 
human  body  is  replaced  by  fresh  material 
in  a  period  which  by  some  whimsical  fancy 
has  been  fixed  at  seven  years.  As  a  matter  of 
fact,  some  cells  are  formed,  pass  to  maturity, 
and  perish  almost  daily,  while  others  last 
as  long  as  the  animal  itself.  Many  of  these 
latter  cells  form  master-cells  of  the  body,  of 
vital  importance,  and  their  decay  determines 
the  downfall  of  the  whole  vast  community. 
Such  cells  are  to  be  found  in  the  brain  and 
other  parts  of  the  central  nervous  system,  in 
arterial  walls,  and  in  mechanisms  which 
control  the  heart.  As  age  advances  the  work 
of  these,  and  other  cells,  alters,  and  chemical 
products  are  thrown  out  and  accumulate 
which  sow  the  seeds  of  decay.  Decline  and 
death  are  accordingly  part  of  a  normal 
process  just  as  much  as  birth  and  growth  are 
at  the  early  parts  of  the  course  of  life,  and,  so 
far  as  our  present  knowledge  leads  us,  all  we 
can  hope  for  is  by  watchful  care  to  prevent 
earlier  decay  by  seeing  to  it  that  these  delicate 
mechanisms  are  not  clogged  and  poisoned  by 
effete  products  of  a  poisonous  nature  manu- 
factured by  wrongful  habits  of  life,  either  in 
the  body  itself,  or  added  from  without  by 
unsuitable    nutrition,    or    the    invasions    of 


46     ORIGIN  AND  NATURE  OF  LIFE 

disease.  Even  this  much  would  be  a  great 
triumph,  for  it  lies  within  our  power  as  a  race 
practically  to  abolish  infectious  diseases  and 
wrongful  habits,  which  are  responsible  for 
half  the  deaths,  and  four-fifths  of  the  disease 
and  suffering  which  afflict  humanity. 

After  all,  it  is  the  happiness  of  health  during 
an  allotted  span  rather  than  mere  length  of 
days  that  is  the  greatest  gain.  The  suffering 
entailed  by  disease  during  life  is  a  real  evil 
compared  with  which  death  at  a  ripe  old  age 
is  only  a  chimerical  misapprehension. 

Returning  to  the  question  of  the  atomic 
constitution  of  matter,  it  may  be  pointed  out 
that  the  view  that  matter  which  enters  into 
chemical  combinations  such  as  form  the 
inorganic  constituents  of  the  earth  and 
the  living  bodies  of  plants  and  animals,  is 
particulate,  and  built  up  by  unions  in  varying 
combinations  of  eighty  or  more  chemical 
elements,  does  not  exclude  the  view  that  the 
remainder  of  space  is  filled  up  by  non-particu- 
late  matter  of  a  certain  density,  but  possessing 
no  weight  because  it  represents  the  zero  of 
density,  or  mass,  and  cannot  be  separated  or 
weighed.  There  exists  from  this  point  of 
view  no  vacuum  in  space,  and  the  completest 
vacuum  known  is  that  which  contains  only 
this  non-particulate  material,  or  luminiferous 


ELECTRONS    AND    ATOMS         47 

ether,  from  which  by  the  agency  of  energy, 
giving  to  it  stable  forms  of  motion,  particles 
can  be  formed.  Ordinary  ponderable  matter 
consists  of  solutions,  or  suspensions,  in  this 
continuous  imponderable  matter,  and  it  has 
been  seen  that  the  transmission  of  energy 
through  space  has  already  made  the  postu- 
lation  of  such  a  medium  necessary  for  the 
physicist. 

The  study  of  radio-activity  has  disclosed 
intermediate  stages  between  the  chemical 
atom  and  the  unformed  pre-matter,  or  lumini- 
ferous  ether,  which  are  of  high  interest  from 
the  point  of  view  of  evolution. 

When  the  different  types  of  radio-activity 
produced  either  by  an  X-ray  tube  or  a  radio- 
active substance,  such  as  a  salt  of  uranium 
or  radium,  are  examined  it  is  found  that  these 
can  in  each  case  be  resolved  into  three  types, 
which  are  distinguished  by  letters  of  the  Greek 
alphabet  as  alpha  (a),  beta  (0),  and  gamma  (y), 
radiations  respectively.  They  are  distinguished, 
amongst  other  things,  by  their  relative 
penetrating  powers  for  substances  such  as 
the  metals  which  are  opaque  to  radiant  light 
or  heat.  The  metal  aluminium  is  used  as  a 
standard,  and  it  has  been  found  that  while 
the  alpha  rays  are  readily  stopped  by  a 
piece  of  aluminium  leaf  of  0.05  of  a  milli- 


48     ORIGIN  AND  NATURE  OF  LIFE 

metre  (or  about  1 -500th  of  an  inch)  in  thick- 
ness, it  requires  5  millimetres  of  aluminium 
to  get  rid  of  the  beta  rays  nearly  completely, 
and  a  column  of  about  50  centimetres,  or 
twenty  inches,  in  English  measure,  is  calcu- 
lated to  be  necessary  for  the  absorption  of 
gamma  rays.  The  relative  penetrating  powers 
are  thus  approximately  as  1  :  100  :  10,000. 

While  the  alpha  and  beta  rays  consist  of 
minute  particles,  the  size  and  energy  content 
of  which  can  be  accurately  measured  and 
their  actual  mass  determined,  the  gamma 
rays  are  waves  or  disturbances  in  the  ether 
propagated  in  irregular  pulses  or  surges  with 
the  velocity  of  light. 

It  is  the  alpha  and  beta  particles  which 
interest  us  chiefly  here  as  being  the  initial 
stage  in  the  synthesis  of  matter,  and  the 
commencement  of  that  long  train  of  interplay 
between  matter  and  energy  which  leads  up 
in  increasing  complexity  of  molecular  structure 
and  attendant  change  in  the  inhabiting 
energy  till  man  is  reached. 

The  beta  particle  is  by  far  the  smaller 
of  the  two,  and  is  identical  with  the  electron, 
or  electricity  bearer.  The  form  of  energy 
which  it  carries  is  electricity,  and  it  is  the 
movement  of  a  constant  stream  of  millions 
of  millions  of  such  beta-particles  or  electrons 


ELECTRONS    AND    ATOMS         49 

along  an  electric  wire  or  other  conductor 
which  constitutes  an  electric  current.  These 
minutest  of  all  particles  may  be  deflected  out 
of  their  straight  course  when  they  are  in 
motion  by  a  charged  surface  placed  parallel 
to  their  flight,  or  by  a  magnet,  and  the  course 
of  deflection  is  the  same  as  that  of  a  stone  or 
bullet  flying  through  the  air.  From  the 
velocity  and  the  deflection  and  other  experi- 
mental data  the  mass  of  the  particle  and  the 
value  of  the  electrical  charge  upon  it  can  be 
calculated.  The  mass  of  the  electron  lies 
between  the  ^^-th  and  ^^th  of  that  of  a 
hydrogen  atom.  Since  such  electrons  can 
be  obtained  either  by  spontaneous  disruption 
of  radio-active  bodies,  or,  by  means  of  electric- 
energy,  from  ordinary  stable  forms  of  matter, 
they  are  believed  to  be  the  constituents  of 
ordinary  atoms  from  which  such  atoms  are 
built  up. 

The  alpha-particle  differs  from  the  beta- 
particle  in  two  chief  ways,  first,  the  alpha- 
particle  carries  a  positive  charge  of  electricity, 
as  is  shown  by  the  fact  that  it  is  deflected  in 
the  opposite  direction  to  the  beta-particle  by 
a  magnet  or  an  electrically  charged  body, 
and  secondly,  by  the  fact  that  it  is  many 
times  larger,  possessing  twice  the  mass 
approximately  of  a  hydrogen  atom.     When 


50     ORIGIN  AND  NATURE  OF  LIFE 

the  alpha-particle  impinges  on  solid  matter 
it  penetrates  some  way,  loses  its  electrical 
charge,  and  slowly  diffuses  out  again  as  an 
atom  of  helium,  one  of  the  chemical  elements 
discovered  in  recent  years. 

This  helium  is  the  lightest  member  of  the 
group  of  inactive  gases,  of  which  the  first 
member  was  discovered  as  a  natural  con- 
stituent of  the  atmosphere  by  Ramsay  and 
Lord  Rayleigh,  and  named  argon.  Several 
other  members  of  the  group  were  later 
discovered,  by  Ramsay  and  his  co-workers, 
and  helium  is  probably  the  most  interesting 
of  the  group  from  the  circumstances  of  its 
discovery  and  its  proven  relationship  to 
inorganic  evolution.  These  elements  are  all 
very  inert  gases  which  have  not  yet  been  found 
in  chemical  union  with  each  other  or  with 
any  other  bodies.  So  inert  are  they  chemically 
that  their  atoms  do  not  even  unite  in  pairs 
with  one  another  to  form  those  dual  atoms, 
or  molecules,  which  are  nearly  always  the 
characteristic  form  in  which  chemical  elements 
higher  in  the  scale  of  evolution  unite  when 
obtained  in  the  free  elemental  form  by  chemi- 
cal manipulation.  When  chemical  science 
does  succeed  in  uniting  the  members  of  this 
series  amongst  themselves,  or  causes  them  to 
reduplicate,  it  will  probably  be  found  that 


EVOLUTION   IN   THE    SUNS       51 

what  has  been  obtained  is  not  a  chemical 
compound  in  the  ordinary  sense  of  the  term, 
but  a  chemical  element  higher  up  in  the 
periodic  scale,  and  in  all  likelihood  one  of 
those  with  which  we  have  long  been  familiar. 
This  group  of  inert  gases  is  conceivably  a 
halfway  stage  between  electrons  and  ordinary 
elements,  requiring  more  electrons  to  be 
added  on,  or  a  union  of  two  such  gases, 
but  as  yet  the  necessary  conditions  are 
unknown  for  the  energy  transformations,  or 
the  electronic  synthesis. 


CHAPTER   III 

CHEMICAL  EVOLUTION  IN  THE  SUNS 

The  history  of  the  discovery  of  helium  is  one 
of  the  most  fascinating  chapters  in  the  whole 
of  science  not  merely  in  regard  to  the  manner 
in  which  the  knowledge  came,  but  also 
because  of  the  gradually  dawning  conviction 
which  it  awakened  in  regard  to  cosmic 
synthesis. 

In  order  to  appreciate  the  beauty  of  the 
discoveries  in  stellar  chemistry  and  their 
relationship  to  the  discovery  of  helium,  some 


52     ORIGIN  AND  NATURE  OF  LIFE 

short   outline   of  spectroscopic  investigation 
becomes  necessary. 

Each  chemical  element  as  it  is  raised  to  an 
incandescent  heat,  or  becomes  radiant  in  a 
vacuum  bulb  through  which  a  high  tension 
electrical  current  is  sent  from  an  electric  coil, 
takes  on  a  rate,  or  a  number  of  rates,  of 
periodic  vibration  of  its  own  of  enormous 
rapidity.  As  a  result  of  this,  the  element 
gives  out  light  of  a  character  peculiar  to  it. 
This  light  when  sent  through  a  prism  does  not 
form  a  continuous  coloured  spectrum  in 
which  all  colours  are  represented  by  light 
waves  of  different  frequency,  but  consists 
rather  of  a  number,  few  or  many,  of  bright 
lines.  When  a  spectrum  of  the  incandescent 
element  is  obtained  by  passing  the  light 
emanating  from  it  through  a  spectroscope, 
a  series  of  distinctive  bright  lines  is  obtained 
which  discloses  the  identity  of  the  element 
as  unmistakably  to  the  spectroscopist  as  a 
thumb-print  does  the  identity  of  an  individual. 
Also,  it  is  known,  that  if  light  from  another 
source,  such  as  a  gas  burner,  which  would 
otherwise  give  a  continuous  bright  spectrum, 
is  passed  through  the  vapour  of  an  element 
at  a  high  temperature,  then  that  element 
absorbs  just  the  light  which  it  would  itself 
give  out  if  it  were  incandescent,  as  described 


EVOLUTION   IN   THE   SUNS       53 

above.  The  result  is  that  what  otherwise 
would  be  a  continuous  bright  spectrum  is  now 
marked  by  dark  lines  corresponding  to  the 
proper  bright  lines  of  the  incandescent 
condition  of  those  elements  that  the  light  has 
passed  through. 

For  example,  in  the  case  of  the  element 
sodium,  which  occurs  in  common  salt,  it  is 
found  that  if  a  spectroscope  be  turned  to  a 
colourless  flame  such  as  that  of  a  spirit-lamp 
or  of  a  Bunsen  burner,  and  some  common  salt 
is  then  volatilized  in  the  flame,  so  producing 
a  yellow  flame,  arising  from  the  atomic 
vibrations  of  the  sodium  atoms  in  the  flame, 
then,  in  the  spectrum  two  bright  yellow 
lines  close  together  are  seen,  and  this  is  the 
only  spectrum  visible.  The  reason  is  that 
this  is  the  only  rate  at  which  sodium  atoms 
produce  optical  vibration  waves.  If  now  the 
spectroscope  be  turned  towards  the  sun  so  as 
to  obtain  the  spectrum  of  sunlight,  the 
complementary  phenomenon  is  seen.  The 
solar  spectrum  consists  of  a  bright  band  of 
colour  ranging  from  red  to  violet,  but  it  is 
interrupted  by  a  great  series  of  thin  black 
lines,  and  the  point  of  interest  is  that  two  of 
these  lines  lying  close  together  in  the  yellow 
are  in  the  exact  position  of  the  two  sodium 
lines  of  the  sodium  flame.     In  photographic 


54     ORIGIN  AND  NATURE  OF  LIFE 

language  the  one  spectrum  is  the  negative 
of  the  other.  The  connecting  link  is  found 
when  the  light  from  such  a  source  as  a  gas 
burner  is  sent  through  hot  sodium  vapour, 
for  now  a  spectrum  is  obtained  identical  with 
the  solar  spectrum  so  far  as  these  two  sodium 
lines  are  concerned.  The  two  lines  now 
show  up  black  like  two  fine  ink  lines,  in  an 
otherwise  continuous  spectrum. 

The  conclusion  is  inevitable.  From  the 
white-hot  central  part  of  the  sun  called  the 
photosphere,  which  would  yield  a  continuous 
spectrum,  the  light  passes  through  an  upper 
zone  or  chromosphere  which  contains  volati- 
lized sodium.  By  exactly  similar  reasoning 
and  experimentation  the  vapour  or  chromo- 
sphere of  the  sun  between  the  internal  white- 
hot  mass  and  our  earth  has  been  shown  to 
contain  a  large  number  of  our  terrestrial 
elements,  some  of  them  in  a  partially  evolved 
form  as  proto-elements. 

This  is  the  simple  basis  of  stellar  chemistry, 
and  for  some  years  now  many  other  suns 
than  the  centre  of  our  planetary  system  have 
been  carefully  charted  as  to  their  spectra, 
and  classified  as  to  their  temperature  and 
chemistry.  Terrestrial  chemistry  has  learnt 
much  from  these  terrifically  hot  furnaces 
set  in  the  heavens,   giving  human  observa- 


EVOLUTION   IN   THE    SUNS       55 

tion  an  opportunity  which  would  be  totally 
unrealizable  on  earth  of  observing  the  effects 
of  high  temperatures  and  the  results  upon  the 
constitution  of  matter.  The  nebulae  have  been 
similarly  studied  and  chemically  classified. 
At  these  spots  in  the  universe  temperatures 
exist  far  exceeding  such  as  are  producable 
upon  earth  by  artificial  means,  and  cosmic 
history  may  be  studied  from  which  lessons 
may  be  derived  as  to  what  happened  millions 
of  years  ago  in  the  history  of  our  earth,  and 
how  the  elements  and  substances  found  to-day 
upon  the  earth's  crust  gradually  came  to  be 
formed.  It  is  only  by  supplying  this  chapter 
that  the  mind  can  be  brought  into  proper 
training  for  understanding  how  life  arose, 
much  as  one  movement  in  a  symphony  pre- 
pares the  mind  and  senses  for,  and  leads  on 
to  another. 

In  the  solar  and  stellar  spectra  as  photo- 
graphed and  charted  by  the  use  of  the  most 
powerful  telescopes  and  delicate  spectroscopic 
apparatus,  many  thousands  of  lines  are  visible 
in  definite  positions.  Some  of  these  lines  are 
very  strong  and  visible  with  ease  through  a 
pocket  spectroscope,  such,  for  example,  as 
the  double  line  or  D  line  of  sodium,  used  as 
an  illustration  in  the  description  above. 
Such  principal  lines  starting  from  the  red 


56     ORIGIN  AND  NATURE  OF  LIFE 

end  of  the  spectrum  and  proceeding  towards 
the  violet  are  named  by  the  capital  letters 
of  the  alphabet,  and  some  of  the  less  marked 
ones  by  the  small  letters.  Such  lines  act  as 
landmarks  in  roughly  assigning  a  position  to 
any  given  line,  or  absorption  band,  in  a  spec- 
trum of  a  substance.  In  this  way  the  spectro- 
scope becomes  a  great  assistant  to  the  chemist, 
and  this  is  not  merely  true  for  the  stellar 
chemist :  the  physiological  chemist  or  bio- 
chemist can  call  in  its  aid  to  detect  and 
identify  many  of  the  coloured  pigments  of 
high  importance  in  the  plant  and  animal 
world.  For  example,  the  red  colouring  matter 
of  the  blood  so  indispensable  to  life,  which 
carries  round  oxygen  for  the  combustion  of 
the  nutrition  of  the  living  cells  derived  from 
the  daily  food,  is  identified  when  placed  before 
even  a  pocket  spectroscope  by  two  specific 
and  distinctive  broad  bands  in  the  red  to  the 
left  of  the  D  line  mentioned  above.  When 
the  bio-chemist  sees  these  two  bands,  he  is 
as  certain  that  he  has  before  him  a  fluid 
containing  blood,  as  any  one  in  ordinary  life 
is  of  the  presence  of  a  well-known  friend  when 
he  looks  him  in  the  face. 

Just  in  the  same  way  the  stellar  chemist 
can  say,  there  is  the  set  of  hydrogen  lines, 
there  are  the  iron  lines,  and  there  the  well- 


EVOLUTION   IN   THE    SUNS       57 

marked  calcium  lines,  in  the  spectrum  of  a 
given  star  or  nebula,  and  with  certainty 
conclude  that  he  is  observing  millions  of 
millions  of  miles  off,  a  body  so  hot  and 
incandescent  that  iron  is  not  merely  molten 
but  vapourized  in  it,  and  even  beyond  that 
stage  is  showing  certain  lines  enhanced, 
as  it  is  termed,  as  on  this  earth  they  only  can 
be  by  a  high  tension  electric  current  sparked 
in  a  vacuum  between  iron  electrodes — a  tem- 
perature hotter  than  anything  which  can  be 
given  by  the  electric  arc  burning  in  air.  It  is 
just  in  such  hottest  suns  that  the  spectra  of 
hydrogen  and  of  the  rare  gases  of  the  group 
produced  in  radio-activity  are  to  be  observed 
in  great  predominance.  Here,  evidently,  at 
this  enormous  temperature,  either  there  is 
visible  before  our  eyes  dissociation  of  matter 
into  its  very  first  and  simplest  forms,  or,  it 
may  be  that  the  available  high  energy 
concentration  at  such  a  temperature  is 
actually  synthesizing  and  producing  from  the 
ether  those  first  steps  in  the  formation  of 
matter.  The  first  process,  or  that  of  disrup- 
tion of  matter,  forms  the  orthodox  view  which 
at  present  holds  the  field,  but  the  second  is 
by  no  means  excluded.  The  chemist  knows 
well  that  it  is  just  at  the  balancing  point 
that  a  reaction  may  run  in  either  direction 


58     ORIGIN  AND  NATURE  OF  LIFE 

varying  with  a  slight  disturbance  towards 
synthesis  or  disruption,  and  also  if  synthesis 
were  taking  place  from  the  luminiferous  ether, 
it  is  just  those  elements  that  are  present  in 
the  hottest  stars  which  would  be  synthesized 
there.  At  different  levels  of  temperature  in 
heating,  or  in  cooling,  at  the  same  time  and 
alongside  of  each  other,  certain  forms  of  matter 
will  be  synthesizing  while  others  are  disrupt- 
ing. 

So  delicately  fixed  are  the  positions  of  the 
well-known  solar  lines  that  a  minute  dis- 
placement towards  either  red  or  blue  end  of 
the  spectrum  at  once  arrests  the  attention  of 
the  stellar  spectroscopist.  Just  as  the  pitch 
of  a  motor  horn,  or  railway  locomotive  whistle, 
is  higher  as  the  car  rapidly  approaches  the 
auditor,  and  falls  as  the  car  moves  away  after 
passing,  so  if  a  star  from  which  the  light  is 
coming  is  approaching  the  earth  with  great 
speed,  the  optical  pitch  of  each  light  of  every 
frequency  will  be  increased,  and  all  the  lines 
will  be  moved  slightly  towards  the  blue  end, 
and  conversely  if  the  star  is  receding.  The 
displacement  is  only  slight,  for  even  the  high 
velocity  of  the  heavenly  bodies  relatively  to 
one  another  is  small  relatively  to  the  velocity 
of  light  moving  at  nearly  200,000  miles  per 
second. 


EVOLUTION    IN    THE    SUNS       59 

Now,  on  looking  at  a  stellar  spectrum  such, 
for  example,  as  that  of  our  own  sun,  the  stellar 
chemist  is  soon  able  to  pick  out  many  familiar 
series  of  lines  as  those  belonging  to  well-known 
terrestrial  elements,  but  in  addition  to  these 
there  are  many  which  are  not  known  terres- 
trially although  the  number  of  these  latter 
is  diminishing  as  research  proceeds.  Another 
interesting  point  is  that  spectra  of  different 
suns  differ  from  one  another.  Some  are  quite 
like  that  of  our  own  sun,  such  as  the  spectrum 
of  the  star  Arcturus,  while  others  show  a 
considerable  difference.  If  the  spectra  of  a 
large  number  of  suns  are  frequently  compared 
until  the  trained  observer  begins  to  grow 
familiar  with  them,  certain  series  of  lines 
become  associated  as  being  always  absent 
from  or  present  in  a  spectrum  together,  and 
so  are  proven  to  be  related  to  a  common  cause, 
and  probably  to  belong  to  the  same  element 
present  in  some  suns  and  absent  in  others. 
In  this  way,  some  years  ago,  Lockyer  had 
connoted  a  series  of  lines  containing  three 
prominent  lines  and  had  ascribed  these  to  an 
element  unknown  terrestrially,  which  he 
provisionally  named  helium,  from  its  presence 
in  our  own  sun's  spectrum. 

For  some  years  this  element  was  entirely 
unknown  upon  earth,  but  after  Ramsay  had 


60     ORIGIN  AND  NATURE  OF  LIFE 

discovered  the  argon  group  of  gases  in  the 
earth's  atmosphere,  he  was  engaged  in  a 
search  amongst  minerals  for  evidences  of  such 
gases,  or  any  new  members  of  the  group, 
occluded  or  fixed  in  the  minerals.  In  the 
course  of  his  investigations,  he  undertook 
the  examination  of  a  mineral  called  cleveite, 
which,  when  heated,  gave  off  a  mixture  of 
gases.  When  a  minute  amount  of  this  gas 
was  introduced  into  a  vacuum  tube,  sparked 
with  an  electric  coil  and  the  spectrum  of  the 
spark  examined,  there  were  actually  found  in 
the  exact  positions  the  characteristic  lines  of 
Lockyer's  celestial  helium.  So,  for  the  first 
time,  an  element  was  discovered  in  the  heavens 
and  then  found  later  upon  earth. 

The  next  triumph  was  the  joint  discovery 
by  Ramsay  and  Soddy  that  when  radium  is 
undergoing  spontaneous  disintegration,  the 
alpha  particles  are  nothing  more  than  charged 
helium  which  had  previously  formed  a  portion 
of  elemental  radium. 

In  the  present  year  Ramsay  and  Collie  have 
shown  that  helium,  along  with  another  gas  of 
the  argon  group,  called  neon,  appears  after 
long  continued  action  of  X-ray  bulbs,  and 
accumulates  in  the  glass  of  the  bulbs  where  the 
radio-active  matter  strikes  the  glass.  The 
glass  at  such   places  also  turns  a  beautiful 


EVOLUTION   IN   THE   SUNS       61 

purple,  due,  it  has  been  supposed,  to  potassium 
liberated  in  the  glass  from  the  chemical  - 
disintegration  of  the  material  of  the  glass 
caused  by  the  electronic  bombardment. 

It  is  a  well-known  fact  to  all  radiographers 
that  X-ray  bulbs  undergo  slow  changes  in 
their  qualities  on  account  of  changes  in  the 
nature  of  the  vacuum  within  the  bulb.  This 
subject  demands  more  investigation  than  it  has 
hitherto  received.  The  common  view  at  the 
present  time  is  that  helium  and  the  electrons 
(or  alpha  and  beta  particles)  produced  in  X-ray 
bulbs  are  detached  from  the  material  of  the 
negative  electrode,  but  proof  of  this  is  lacking, 
and  it  may  well  be  that  the  electric  energy 
really  synthesizes  these  first  forms  of  matter 
from  the  luminiferous  ether  which  fills  the 
bulb.  A  strong  point  against  the  origin  of 
helium  and  electrons  being  from  disintegra- 
tion of  more  highly  synthesized  material  of 
bulb  or  electrodes  is  that  the  electrons  are 
invariably  the  same  whatever  the  material 
of  the  electrodes,  while  the  disintegration 
products  of  varying  chemical  molecules  or 
atoms  should  show  great  variations,  as,  for 
example,  a  pulverized  rock  would  show  the 
nature  of  its  origin  in  the  minute  particles. 
Also  the  number  of  exactly  similar  electrons 
is  enormous  compared  to  the  yield  of  rare 


62     ORIGIN  AND  NATURE  OF  LIFE 

gases.  Now,  theoretically,  electrons  must  be 
identical  whatever  their  origin,  and  so,  if  the 
source  were  disintegration,  there  ought  to  be 
much  of  the  intermediate  products,  such  as 
helium,  xenon,  neon,  argon,  and  hydrogen,  and 
little  of  the  single  constituents  or  ultimate 
fragments.  But  if  the  source  were  synthesis 
from  the  ether,  it  might  be  suspected  that 
there  would  be  much  of  the  first  stage  of 
synthesis  or  electrons,  and  fewer  of  the 
more  complex  products  or  rare  gases.  The 
second  is  what  is  found  experimentally,  but 
it  may  well  be  that  in  any  such  active  electrical 
discharge  both  synthesis  and  disintegration  of 
matter  go  on  alongside  of  each  other,  and  that 
a  study  of  experimental  conditions  will  allow 
us  in  the  future  to  cause  whichever  we  choose 
to  predominate. 

It  has  been  said  above  that  the  spectra  of 
different  stars  show  important  differences, 
and  this  not  only  gives  a  guide  to  a  classifica- 
tion of  the  stars  according  to  their  temperature 
but  yields  important  evidence  in  regard  to 
evolution  at  the  inorganic  stage.  The  evi- 
dence is  that  the  same  element  is  in  different 
conditions  at  different  temperatures,  and 
also  that  at  lower  temperatures  certain  ele- 
ments exist  which  disappear  at  higher  tem- 
peratures, and  are  replaced  by  others,  these 


EVOLUTION    IN   THE    SUNS       63 

latter  elements   being   absent   at  the  lower 
temperatures. 

In  studying  this  subject  the  same  element, 
such,  for  example,  as  iron,  may  be  experi- 
mented upon  at  different  temperatures,  and 
when  this  is  done,  remarkable  changes  are 
seen  as  higher  temperatures  are  reached. 
In  the  flame  of  the  spirit-lamp  or  a  Bunsen 
burner,  the  lines  of  sodium,  as  has  been  said 
above,  are  easily  produced,  but  a  metal  like 
iron  shows  nothing.  In  the  blow-pipe  flame, 
the  iron  shows  the  dawning  of  a  spectrum 
by  giving  series  of  bands  or  flutings,  a  "  fluted 
spectrum,"  as  it  has  been  termed.  When  the 
energy  of  the  voltaic  arc  has  been  reached  by 
sending  a  strong  current,  such  as  is  used  by 
electric  tramcars  or  for  lighting,  between  poles 
made  of  iron,  then  a  line  spectrum  is  first 
reached  for  iron,  and  this  shows  thousands  of 
lines  specific  for  iron  at  such  a  temperature. 
Flame  arcs  yielding  light  which  would  give 
such  spectra  are  often  seen  between  wheel  and 
rail  of  a  tramcar  when  vibration  of  the  car 
or  some  dirt  upon  the  rails  has  temporarily 
broken  contact,  and  an  iron  arc  is  formed. 
A  similar  copper  arc  is  also  frequently  seen 
above  when  the  trolley-wheel  leaves  the  over- 
head conducting  wire,  and  for  a  moment  a  cop- 
per arc  is  established.     The  now  well-known 


64     ORIGIN  AND  NATURE  OF  LIFE 

green  light  of  the  mercury  arc  lamp  is  another 
example  of  a  metallic  arc  which  would  give 
the  mercury  spectrum.  The  spectrum  given 
by  the  electric  potential  of  the  ordinary  voltaic 
arc  and  produced  at  the  high  temperature  of 
this  electric  furnace,  is  not,  however,  the  last 
word  as  to  what  can  be  done  in  the  way  of 
temporary  disintegration  of  the  more  perma- 
nent metallic  elements  into  what  have  been 
termed  by  Lockyer,  proto-metals. 

Other  forms  of  energy  at  a  high  pressure  or 
potential  seem  to  possess  a  power  of  causing 
atomic  disintegration  which  heat  alone  does 
not  possess,  for  the  electric  pressure  in  the 
ordinary  arc-flame  in  air  is  so  low  compara- 
tively, that  the  chemical  effects  Jiere  must  be 
ascribed  almost  solely  to  the  great  heat  pro- 
duced in  the  crater  of  the  arc  by  the  conver- 
sion of  large  quantities  of  electrical  energy  at 
low  pressure  into  heat.  This  operation  is  like 
using  the  energy  of  a  large  river  of  water 
falling  only  a  small  height. 

When,  instead  of  the  ordinary  air-arc, 
recourse  is  had  to  an  arc  in  a  high  vacuum 
spark-gap  several  inches  in  length  across  which 
high  tension  electricity  at  an  enormous  pres- 
sure of  some  hundreds  of  thousands  of  volts 
is  made  to  leap,  then  a  new  set  of  phenomena 
at    once    make    their    appearance,    and    the 


EVOLUTION   IN   THE    SUNS       65 

spectra  in  the  case  of  most  metals  become 
entirely  changed,  showing  that  a  new  stage 
in  the  disintegration  of  the  metal  has  been 
reached.  For  example,  the  iron  arc-spectrum 
of  the  voltaic  arc  contains  some  thousands  of 
lines,  as  if  the  iron  atom  might  be  regarded 
almost  as  a  planet  which  by  the  agency  of  the 
intense  heat  of  the  arc  had  been  split  into 
thousands  of  meteorites.  But  at  the  conditions 
of  the  vacuum  spark  spectrum,  these  thousands 
of  lines  have  disappeared,  and  become  re- 
placed by  a  few  much  more  strongly  marked 
lines,  three  of  which  are  especially  characteris- 
tic. These  lines,  from  their  strength  and  their 
persistence  in  greater  intensity  when  the  others 
have  disappeared,  are  called  the  "  enhanced  " 
lines  of  iron.  Now,  apart  altogether  from 
stellar  spectroscopy,  this  series  of  changes 
in  the  lines  of  a  metallic  spectrum  most 
strongly  indicates,  if  indeed  it  does  not 
prove,  a  corresponding  change  in  the  ele- 
mental constitution  of  the  metal  while  under 
the  energy-environment  of  the  air-arc  or 
spark-gap  respectively,  and  it  will  presently  be 
seen  that  under  energy  conditions  which  we 
cannot  at  present  attain  upon  earth,  even  the 
spark-spectrum  of  certain  metals  disappears 
at  certain  levels,  showing  still  more  complete 
disruption.     The    many-lined    arc    spectrum 


66     ORIGIN  AND  NATURE  OF  LIFE 

of  iron  would  appear  to  indicate  a  position 
with  many  unstable  intermediate  disruption 
products  of  iron,  which  passes  on  by  the 
break-up  of  these  into  the  small  number 
of  stable  products  (under  the  given  energy- 
environment)  represented  by  the  small  num- 
ber of  enhanced  lines  of  the  vacuum  spark 
spectrum. 

The  next  step  in  the  chain  of  evidence 
of  the  evolution  of  the  elements  is  that  when 
the  spectroscope  is  turned  toward  the  sun 
there  most  clearly  seen  are  the  important 
enhanced  iron  lines  of  the  vacuum- spark 
spectrum,  and  no  trace  of  the  multitudinous 
lines  of  the  iron  air-arc  spectrum  is  to  be  seen. 
What  conclusion  can  be  drawn  save  that  iron 
exists  not  merely  as  vapour  in  the  sun,  but  as 
vapour  elementally  decomposed  to  the  stage 
at  which  it  is  found  in  a  vacuum  spark- 
break  spanned  by  an  electrical  tension  of  a 
hundred  thousand  volts  ? 

There  exists  at  present  no  form  of  thermo- 
metry which  will  enable  us  to  determine 
whether  the  temperature  in  the  actual  spark 
region  is  an  enormous  one,  or  whether  the 
transformations  there  shown  by  the  spectro- 
scope are  directly  electrical  ones.  Certainly 
the  bulb  as  a  whole  does  not  require  a  high 
temperature.     This  point  is  an  important  one 


EVOLUTION    IN   THE    SUNS       67 

because  there  are  many  nebulse  in  which  the 
spectroscopic  findings  would  indicate  a  very 
high  temperature,  yet  other  things  do  not 
favour  such  a  view,  and  it  may  well  be  that 
in  such  regions  electrical  charges  causing 
transformations  of  energy  at  high  potentials 
are  the  causes  at  work.  Also,  in  the  case  of 
our  sun,  there  may  be  other  forms  than  heat- 
energy  at  work  giving  the  spectroscopic 
results. 

If  these  results  of  enhanced  spectral  lines 
as  obse'rvable  in  the  solar  spectrum,  however, 
be  taken  as  due  to  temperature  alone,  then 
the  solar  temperature  far  exceeds  that  of 
the  electric  arc  which  gives  the  highest  tem- 
perature of  matter  en  masse  known  to  us 
terrestrially. 

As  has  been  stated  above,  the  temperature 
of  the  high  tension  vacuum  spark  cannot  be 
measured,  so  meanwhile  it  must  be  left  as  an 
open  question.  Experimentally  the  effect 
that  has  been  obtained  by  passing  from  the 
low-tension  air-arc  to  the  high-tension  arc, 
may  be  expressed  from  the  standpoint  of 
energetics  by  saying  that  in  the  former 
case  a  large  amount  of  matter  has  been  heated 
to  a  high  temperature,  in  which  it  volatilizes 
at  considerable  pressure,  while  in  the  latter 
case  by  concentration  of  much  energy  at  high 


68     ORIGIN  AND  NATURE  OF  LIFE 

pressure  on  an  infinitesimally  small  amount 
of  matter  (a  quite  unweighable  amount  of 
matter),  this  has  been  volatilized  at  a  very 
low  pressure  in  a  vacuum,  and  so  loaded 
with  energy  that  it  disintegrates. 

It  is  the  proof  of  disintegration  that  interests 
us  here  because  that  is  only  the  reverse  of 
synthesis,  and  we  are  studying  how  these 
forms  of  matter  can  originate  by  observing 
how  they  may  be  pulled  apart,  and  what 
happens  then. 

To  any  person  unloaded  mentally  with 
early  training  as  to  the  inviolability  of  the 
chemical  elements  and  the  sacredness  of  the 
conservation  of  the  elements,  the  changes 
above  mentioned  in  the  spectra  would  form 
strong  presumptive  evidence  of  the  composite 
nature  of  iron,  and  similar  proof  exists  in  the 
case  of  other  elements.  But  stellar  spectro- 
scopy possesses  additional  experimental  evi- 
dence which  raises  the  presumption  almost  to 
a  demonstration. 

It  has  been  pointed  out  above  that  a  slight 
deflection  to  right  or  left  of  a  well-known 
line  proved  that  the  material  giving  origin  to 
that  line  was  moving  towards  or  away  from 
the  spectroscope,  so  raising  or  lowering  the 
colour-tone  or  pitch  of  the  light  causing  the 
line.     Now    in    sun-spot    observation,     this 


EVOLUTION    IN    THE    SUNS       69 

remarkable  thing  has  been  seen ;  one  of  the 
enhanced  lines  of  iron  is  stationary,  while  the 
other  two  indicate  motion.  This  amounts  to  a 
proof,  not  merely  that  the  proto-elements  of 
iron  exist  apart  in  the  sun's  atmosphere  as  they 
do  side  by  side  in  the  vacuum  spark  on  earth, 
but  that  immense  translational  velocities  are 
actually  separating  them  from  one  another. 
This  arises  because  one  is  more  stable  at  one 
zone  of  solar  energy  conditions,  and  the  others 
at  other  zones.  Apart  from  iron,  this  has 
been  shown  by  taking  sectional  or  zonal 
spectra  of  the  corona  or  sun's  margin,  in  solar 
eclipses,  and  so  sampling  the  sun's  atmosphere 
at  various  levels  above  the  central  portion. 
While  there  are  enormous  surgings  up  and 
down  the  spectra  show  predominance  of 
different  types  of  matter  at  different  levels, 
and  these  indicate  different  temperatures  (or 
other  energy-distributions)  similar  to  those 
observable  in  many  different  suns,  and  upon 
which  these  stars  have  been  classified  spectro- 
scopically  as  shown  below. 

In  the  sun,  and  incandescent  stars  and 
nebulae,  there  is  not  merely  the  momentary 
separation  by  the  disruptive  electric  discharge 
such  as  can  be  produced  terrestrially,  but  a 
permanent  condition  of  disruption  over  a 
large  field,  as  a  result  of  which  the  constituents, 


70     ORIGIN  AND  NATURE  OF  LIFE 

or  proto-elements,  can  separate  from  one 
another,  or  diffuse  out  as  the  chemist  terms  it. 

The  next  experimental  stage  required 
terrestrially  is  some  mechanism  to  separate 
the  proto-elements  while  the  sparking  is  in 
progress  in  the  vacuum  tube.  If  a  magnetic 
or  electric  field  could  be  utilized  to  deflect 
one  constituent  in  one  direction  and  the 
other  in  the  opposite,  as  can  be  done  at 
present  with  the  alpha  and  beta  particles, 
a  whole  series  of  brilliant  advances  would  be 
made. 

There  is  little  doubt  that  in  time  this 
advance  will  come  and  that  the  chemistry 
of  the  future  will  realize  the  dream  of  the 
alchemist  and  succeed  in  transmuting  one 
element  into  another.  Electrical  energy  will, 
in  all  probability,  take  on  the  r61e  of  the 
philosopher's  stone,  though  at  first  artificial 
gold,  as  artificial  diamonds  are  nowadays, 
may  be  more  expensive  than  natural  gold. 

The  glut  of  gold  does  not,  however,  dim 
the  vision  of  the  modern  thinker ;  he  sees 
higher  and  more  glorious  things  than  this,  and 
is  more  concerned  with  matter  and  energy  at 
more  primeval  stages,  with  the  history  of 
worlds  in  the  making,  with  the  splendid 
continuity  of  nature,  and  the  entrancing 
romance  of  how  life  came  upon  earth,  and 


EVOLUTION    IN    THE    SUNS       71 

step  by  step  went  onward,  creating  the  beau- 
tiful, and,  more  wonderful  still,  introducing 
that  intelligence  which  can  admire  beauty,  and 
can  worship,  not  with  ignorant  obeisance, 
but  in  skilful  and  participating  science  or 
knowledge. 

These  primeval  beginnings  of  the  trans- 
mutations of  matter  and  energy,  with  the 
formation  of  the  proto-elements  and  elements, 
are  illustrated  by  the  present  stages  of  the 
developments  of  worlds,  as  seen  by  the 
astronomer,  in  the  constellations  of  all  ages 
which  surround  this  world  of  ours. 

Armed  with  the  telescope  and  spectroscope, 
we  stand,  as  it  were,  in  an  immense  cosmic 
picture  gallery,  in  which  instead  of  each 
picture  being  finished,  in  many  cases  hundreds 
of  years  ago,  each  picture  is  unfinished,  and  the 
artist  is  at  work  upon  it.  Just  as  in  a  national 
gallery  there  may  be  studied  the  history  and 
evolution  of  art  in  the  past,  so  to-day  in  the 
heavens  and  upon  earth  there  can  be  studied 
the  problem  of  the  evolution  of  nature's 
architecture  of  matter.  What  a  wonderful 
revelation  to  the  historian  and  artist  it  would 
be,  if  instead  of  dead  records  and  finished 
works  executed  in  the  past  by  creative  acts 
consummated  once  for  all  and  never  to  be 
repeated,  the  living  happenings  were  before 


72     ORIGIN  AND  NATURE  OF  LIFE 

his  eyes.  If  he  could  stand  in  a  modern 
gallery  and  see  artists  of  all  ages  and  genera- 
tions at  work,  or  talk  to  writers,  dramatists, 
and  philosophers  of  all  times.  Yet  this  is  what 
the  scientist  possesses  in  living  intensely 
active  nature,  and  this  glorious  thing  it  is 
that  he  is  sometimes  asked  blindly  to  sur- 
render for  a  pre-conceived  unnatural  world 
with  isolated  creative  acts  ended  in  the  distant 
ages  of  the  past,  never  repeated  now,  and  of 
which  the  key  has  been  for  ever  lost. 

Truly  we  are  only  beginning  to  realize  as  in 
a  dream  that  creation  and  the  design  of 
creation  is  something  nobler  than  man's 
intelligence  has  yet  conceived,  that  Nature  is 
not  powerless  to  create  again  such  as  she  has 
once  created  and  is  still  at  work,  and  that  we 
must  look  with  fresh  eyes  and  fresh  interest 
at  things  being  produced  with  eternal  youth 
from  the  womb  of  Nature. 

Continuity,  not  dis-continuity,  is  Nature's 
plan,  and  it  is  only  by  centring  thought 
around  our  own  individual  lives,  whose 
relationships  and  pasts  and  futures  we  do  not 
understand  that  preference  arises  for  dis- 
continuity. The  full  and  true  relationships 
of  the  individual  life  will  only  become  realiz- 
able by  patient  study  of  the  whole  cosmical 
scheme. 


EVOLUTION   IN   THE    SUNS       73 

The  stellar  evidences  of  the  synthesis 
of  matter  and  the  creation  of  worlds,  leaves 
the  position  entirely  untenable,  that  life  once 
came  by  a  single  creative  unrelated  act  upon 
this  earth,  or  any  other  earth  from  which 
it  was  carried  to  ours.  Life  is  at  present 
originating  in  countless  other  worlds  as  daily 
it  is  originating  upon  our  own,  and  given 
a  certain  stage  in  evolution  when  matter  has 
reached  a  certain  complexity  in  structure,  and 
become  tenanted  by  certain  types  of  energy, 
life  must  come,  and  having  come  must  evolve 
into  higher  and  higher  forms. 

The  first  stage  of  all  is  the  evolution  from 
imponderable  proto-matter,  or  ether,  of  the 
electron,  from  the  electron  arise  the  proto- 
elements,  and  from  these  the  inert  gases  of  the 
helium  group  and  hydrogen,  and  by  various 
unions  of  the  proto-elements,  the  elements 
as  we  know  them  at  terrestrial  temperatures 
and  conditions,  arise. 

It  is  an  observation  of  the  highest  interest 
in  the  stellar  evolution  of  the  elements,  as 
has  been  pointed  out  by  Lockyer,  that  it  is  in 
the  hottest  stars  that  the  simplest  forms  of 
matter  are  present,  and  that  the  incandescent 
bodies  of  the  heavens  can  be  classified  on  this 
basis. 

The    following    is    the    classification    pro- 


74     ORIGIN  AND  NATURE  OF  LIFE 

visionally  submitted  by  Lockyer  in  his  book 
on  "  Inorganic  Evolution." 

Classification"  of  Stars  : 
Highest  temperature. 

(  Proto-hydrogen  stars  f  ff^nia? 
a.  Gaseous  Stars  J  frJ  Almtamian. 

Helium-gas  stars  J  Sracian  .^nan 
V  °  (  Taurian    Algohan 

(Rigelian  Markabian 

Cygnian  — 

—  Sirian. 

c.  Metallic  Stars  \     ^an  ^yonian 

I     Aldebanan     Arcturian, 

d.  Stars  with  Fluted  Antarian        Piscian, 

Spectra. 

Lowest  Temperature. 

As  to  the  terminology  used  in  the  above 
table  the  termination  "  ian "  is  used  to 
indicate  an  epoch  or  stage  in  the  process  of 
evolution  much  as  the  same  termination  is 
used  in  geological  evolution  for  the  termination 
of  a  primary  division  of  strata  as  in  the  words 
"  Devonian  "  and  "  Silurian."  As  the  pro- 
cesses are  here  simultaneous  in  different 
worlds,  instead  of  chronological  in  order  in 
one  world,  temperature  takes  the  place  of 
time,  but  the  same  effects  would  happen 
chronologically  could  the  process  be  observed 
in  the  same  sun  over  a  period  of  millions 


EVOLUTION   IN   THE    SUNS       75 

of  years.  The  order  of  evolution  of  the 
elements  would  thus  happen  in  the  same 
fashion  as  the  origin  of  organic  species  in  the 
geological  epochs.  In  geology  the  range  of 
temperature  is  infinitely  shorter,  and  the 
gradient  of  fall  of  temperature  slower,  so 
that  some  millions  of  years  witness  but  the 
fall  of  a  few  degrees  in  temperature. 

The  names  for  the  stellar  epochs  are  derived 
either  from  that  of  a  typical  bright  star  which 
possesses  at  the  present  time  a  temperature 
indicated  by  its  spectrum,  or  sometimes  the 
name  of  the  constellation  in  which  the  star  is 
found.  Where  two  columns  of  names  of  stars 
are  given  those  in  the  first  column  are  stars 
of  which  the  temperature  is  at  present 
supposed  to  be  increasing,  and  where  evolution 
would  be  reversed  or  in  the  direction  of  dis- 
integration. The  second  column  contains 
stars  with  decreasing  temperatures,  where 
elemental  evolution  towards  higher  atomic 
weights  is  progressing.  Our  own  sun  would 
be  placed  in  this  column  at  the  level  denoted 
by  Arcturian. 

The  word  proto-hydrogen  in  the  table 
indicates  that  in  these  hottest  of  all  observed 
suns  (two  suns  in  the  constellation  Argo), 
a  series  of  lines  are  met  with  belonging  to  no 
known  terrestrial  element,  but  standing  in 


76     ORIGIN  AND  NATURE  OF  LIFE 

relationship  to  known  hydrogen  lines,  and 
supposed  to  be  precursors  of  that  element. 
The  other  predominant  lines  at  this  level  of 
stellar  temperature  and  evolution,  are  those 
of  hydrogen  as  seen  terrestrially  when  hydro- 
gen is  sparked  with  an  electric  coil  in  a  vacuum 
tube.  Much  fainter  lines  are  seen  of  helium, 
proto-magnesium,  and  proto-calcium.  No  lines 
of  iron  are  visible  here,  even  in  the  proto- 
form.  Next  come  stars  of  the  helium  group, 
where  the  spectrum  of  that  gas  is  prominent, 
associated  still  with  hydrogen,  and  the  spectral 
lines  of  proto-carbon,  oxygen,  and  nitrogen 
are  now  clearly  present. 

In  the  proto-metallic  stars,  the  precursors 
of  such  metals  as  iron,  copper,  manganese, 
nickel,  titanium,  and  calcium,  make  their 
prominent  appearance. 

When  the  metallic  spectra  are  reached  such 
lines  as  distinguish  calcium,  iron,  and  man- 
ganese in  the  ordinary  voltaic  air-arc  are 
present,  while  many  of  the  proto-lines  become 
dimmer  and  disappear.  Lastly,  the  fluted 
spectra  appear,  of  carbon  or  manganese,  with 
fainter  metallic  lines. 

It  is  thus  seen  that  the  more  primordial 
constituents  of  matter  are  those  formed  in  the 
hottest  stars,  and  that  as  temperature  falls 
the   ordinary   elements  become   synthesized. 


EVOLUTION   IN   THE    SUNS       77 

The  evidence  of  the  heavens  corroborates  that 
given  by  terrestrial  disruption  by  high  tension 
electricity  in  a  vacuum,  by  the  evidence  of  the 
X-ray  bulb,  and  by  that  of  the  radio-active 
disintegration  of  the  atoms  possessing  high 
atomic  weight. 

The  whole  tale  of  elemental  evolution  holds 
together,  is  consistent,  and  leads  to  new  dis- 
coveries. This  is  the  distance  which  stellar 
observation  and  the  study  of  radio-active 
matter  take  us  on  our  journey ;  from  this  point 
the  way  lies  amidst  ordinary  chemical  com- 
binations of  the  elements  amongst  one  another 
to  form  molecular  combinations  or  chemical 
compounds.  There  is  no  breach  of  continuity 
as  we  enter  this  zone,  the  same  laws  of  inter- 
action hold,  but  greater  specific  differences 
in  the  forms  of  matter  arise  ;  there  is  more 
chemical  individuality,  and  there  are  new 
conditions  of  energy  manifestation. 

Thus,  such  a  well-known  substance  as  water, 
as  the  temperature  is  elevated,  would  break 
up  into  the  two  elements,  hydrogen  and 
oxygen,  which  compose  it,  long  before  such  a 
temperature  as  that  of  the  coolest  of  the  stars 
mentioned  above  had  been  reached.  There 
exists  a  temperature,  however,  at  which  a 
mixture  of  steam  (or  gaseous  water)  can 
exist  alongside  of  its  two  constituent  gases, 


78     ORIGIN  AND  NATURE  OF  LIFE 

and  at  a  lower  point  still  these  two  gases  unite 
together  firmly  with  great  discharge  of 
energy.  Lower  still  the  gaseous  water  con- 
denses into  liquid  form.  What  happens  for 
water  happens  for  thousands  of  other  com- 
binations of  the  chemical  elements  which 
are  known  as  chemical  compounds.  Each 
compound  contains  a  definite  number  of 
atoms  of  each  of  two  or  more  chemical  ele- 
ments. 

The  simplest  of  the  compounds,  and  those 
first  formed  in  complexity,  are  the  so-called 
binary  compounds  which  contain  only  two 
elements  present  in  such  amounts  as  corre- 
spond to  some  simple  atomic  relationship. 
For  example,  water  consists  of  two  atoms 
of  hydrogen  and  one  atom  of  oxygen,  and 
common  salt  consists  of  one  atom  of  a 
metallic  substance  called  sodium,  united  to 
one  atom  of  a  gas  called  chlorine,  so  that 
it  possesses  the  chemical  name  of  chloride  of 
sodium. 

In  order  to  understand  something  of  this 
stage  in  evolution  it  becomes  necessary  to 
explain  two  specific  or  individualized  pro- 
perties which  here  begin  clearly  to  differentiate 
the  various  forms  of  matter,  and  are  called 
I  chemical  affinity  and  chemical  valency.  This 
is  the  first  definite  inorganic  dawning  of  that 


CHEMISTRY    OF   THE   EARTH     79 

high  specialization  or  adaptation  which  is 
seen  with  exquisite  refinement  and  balance 
in  living  organisms. 


CHAPTER   IV 

CHEMICAL  COMPOUNDS  ON  EARTH 

After  the  various  forms  of  the  atoms  have 
been  forged  in  the  mighty  furnaces  of  the 
suns,  the  differences  in  atomic  structure  so 
imparted  to  them  cause  them  to  possess 
specific  dynamic  properties  varying  from  one 
sort  of  atom  to  another.  It  is  not  to  be 
supposed  that  the  constituent  groups  of 
electrons  forming  an  atom  are  at  rest  and 
fixed ;  but  rather  that  each  possesses  the 
properties  of  an  infinitely  small  microcosmic 
system  with  constituent  groups  of  electrons 
in  vibrational  or  orbital  movement  in  respect 
to  one  another.  The  atom  is  in  reality  charac- 
terized by  the  amount  of  energy  it  contains, 
and  is  not  to  be  looked  upon  as  a  dead 
mass  with  fixed  motionless  structure.  It  is 
necessary  to  insist  upon  this  because  the 
chemical  symbols  by  which  the  chemist 
attempts  to  fix  and  visualize  the  atoms  with 


80     ORIGIN  AND  NATURE  OF  LIFE 

which  he  is  dealing  produce  a  stereotyping 
effect  on  the  mind,  and  unless  the  student  is 
always  on  the  alert,  he  is  apt  to  come  to 
believe  that  the  atom  is  what  the  symbol 
represents  it  to  be,  a  fixed  or  motionless 
structure,  whereas  it  is  in  reality  a  centre 
of  ever-moving  energy.  It  is  by  virtue 
of  its  dynamical  power  that  it  undergoes 
chemical  transformations  with  building  up  or 
breaking  down  of  chemical  compounds. 

Within  the  limits  of  ordinary  chemical 
reaction  no  changes  of  sufficient  violence 
occur  to  invade  the  energy  equilibrium  of 
the  constituent  groups  of  electrons  constitut- 
ing the  atoms,  so  the  atom  may  be  regarded 
as  stable,  indestructible,  and  indivisible  in  the 
sense  explained  in  the  previous  chapter. 

The  atom  may  accordingly  be  accepted  by 
the  chemist  as  a  working  unit  just  as  the 
biologist  still  accepts  the  living  constituent 
cell  of  the  plant  or  animal  as  a  biological 
unit,  and  the  facts  of  the  preceding  chapter 
need  no  more  invalidate  this  position,  than 
the  corresponding  fact  in  quite  modern  biology 
that  many  of  the  properties  of  the  cell  may 
be  carried  on  by  isolated  parts  of  the  cell, 
which  a  few  years  ago  were  only  considered 
possible  for  the  entire  and  undivided  cell  to 
perform. 


CHEMISTRY    OF    THE    EARTH     81 

Each  one  of  the  chemical  atoms  possesses  a 
different  weight,  which  is  utilized  as  an 
indicator  of  the  amount  of  matter  in  it.  Until 
quite  recently  the  absolute  masses  of  the 
atoms  were  unknown  to  us,  it  is  one  of  the 
many  triumphs  of  the  study  of  radio-activity 
that  we  now  know  them,  but  for  ordinary 
chemical  operations  it  is  only  necessary  to 
know  their  relative  weights  and  these  relative 
weights  are  what  are  known  as  the  atomic 
weights  of  the  elements. 

When  two  or  more  elements  unite  to  form  a 
chemical  compound,  the  masses  taking  part 
in  the  reaction  are  always  so  related  that 
they  may  be  expressed  as  simple  multiples 
of  the  atomic  weights.  This  shows  that 
always  a  definite  number  of  atoms  enter  into 
the  formation  of  each  compound,  and  it  is  for 
this  reason  that  under  similar  conditions  of 
environment,  all  the  characters  of  a  chemical 
compound  are  absolutely  definite  and  in- 
variable. Thus  two  atoms  of  hydrogen  al- 
ways combine  with  one  atom  of  oxygen  to 
form  what  is  termed  a  molecule  of  water,  and 
never  in  any  other  ratio  or  proportion  is 
water  formed.  Thus  one  molecule  of  water  is 
always  precisely  similar  to  another  molecule, 
and,  hence,  in  the  mass,  or  bulk,  if  water  be 
quite  unmixed  with  anything  else,  one  sample 


82     ORIGIN  AND  NATURE  OF  LIFE 

of  water  is  the  same  in  all  its  qualities  as 
another  sample.  Two  atoms  of  hydrogen 
unite  with  one  of  oxygen  to  form  water,  but 
if  hydrogen  and  the  yellowish  gas  with  bleach- 
ing properties  called  chlorine  happen  to  be 
the  two  kinds  of  atom  uniting,  then  it  is  found 
that  one  atom  of  hydrogen  and  one  atom  of 
chlorine  unite,  and  the  product  of  their  union 
is  called  hydrochloric  acid. 

In  another  case,  when  one  atom  of  an 
element  called  nitrogen,  which  forms  the 
prodominant  component  of  the  atmosphere, 
unites  with  three  atoms  of  hydrogen,  there  is 
formed  the  molecule  of  the  gaseous  body  which 
we  term  ammonia.  Again,  if  one  atom  of 
the  solid  element  carbon  unites  with  four 
atoms  of  hydrogen  there  is  formed  a  gas  known 
as  marsh  gas,  or  methane.  As  a  final  example, 
there  may  be  mentioned  the  liquid  substance, 
chloroform,  of  which  one  molecule  is  formed 
by  the  union  of  one  atom  of  carbon,  with  one 
atom  of  hydrogen,  and  three  atoms  of  the 
above-mentioned  gas,  chlorine.  These  parti- 
cular examples  have  been  chosen  in  illustra- 
tion, for  a  special  purpose  which  will 
become  obvious  presently.  The  points  to  be 
observed  at  present  are  two,  namely,  that 
there  is  always  a  definite  number  of  atoms  of 
each  kind  of  constituent  element,  and  secondly 


CHEMISTRY   OF  THE   EARTH     83 

that  sometimes  the  atoms  unite  in  the  ratio 
of  one  to  one,  at  other  times  two  to  one,  or 
three  to  one,  or  even  as  in  the  case  of  carbon 
and  hydrogen,  four  to  one. 

As  there  are  eighty  or  more  forms  of  ele- 
mental matter,  and  as  there  may  be  from  two  to 
as  many  as  six  or  seven  different  elements,  and 
these  in  different  arrangement  and  numbers  of 
atoms,  in  the  compounds,  it  follows  that  the 
number  of  chemical  compounds  is  legion.  For 
out  of  twenty-six  letters  in  the  alphabet  any 
number  of  words  may  be  formed,  and  three 
or  four  words  on  the  back  of  an  envelope  will 
take  a  letter  safely  to  one  of  many  million 
individuals.  And,  as  the  individuals  are 
arranged  in  countries  and  communities  and 
families,  so  also  the  groups  of  chemical  com- 
pounds are  related  and  organised  and  arranged, 
and  a  great  part  of  the  science  of  chemistry 
consists  of  the  study  of  their  organisations 
and  relationships. 

Space  forbids  us  entering  into  details  of 
such  study,  it  will  be  sufficient  for  our  present 
purpose  to  point  out  that  these  elements 
unite  with  one  another  with  very  varying 
degrees  of  intensity,  or  as  the  chemist  ex- 
presses it,  possess  varying  chemical  affinities 
for  one  another,  and,  secondly,  that  in  uniting 
they  possess  different  valencies,  or  chemical 


84     ORIGIN  AND  NATURE  OF  LIFE 

values,  for  satisfying  or  saturating  one  an- 
other. These  two  properties  of  affinity  and 
valency  lead  to  formation  of  the  chemical 
compound,  or  single  chemical  molecule,  which 
carries  us  the  next  step  forward  in  the  process 
of  evolution  leading  towards  life. 

The  varying  degrees  of  affinity  may  be 
illustrated  everywhere  in  chemistry  with  the 
greatest  ease,  our  own  lives  depend  upon 
such  varying  affinities  at  every  moment, 
and  chemical  affinity  is  seen  daily  in  varying 
degree  in  all  the  familiar  objects  around  us. 
But  perhaps  the  best  example  to  place  before 
the  non-chemist  is  that  seen  in  the  rusting  or 
oxidation  of  metals.  It  is  well  known  that 
gold  remains  bright  in  the  air,  while  silver 
slowly  tarnishes,  lead  tarnishes  quite  rapidly, 
copper  turns  green,  and  iron  coats  itself  with 
a  red  rust.  These  metals  are  all  elements, 
and  their  rusting  or  tarnishing  is  due  to  their 
surface  layer  uniting  with  the  oxygen  of  the 
air  to  form  chemical  compounds  known  as 
oxides.  The  familiar  occurrences  mentioned 
above  illustrate  varying  degrees  of  chemical 
affinity.  Now,  by  methods  which  need  not 
be  described  here,  the  chemist  can  measure 
the  amount  of  energy  set  free  or  absorbed 
when  elements  unite,  and  so  obtains  measures 
for    the     chemical    affinity.      As    a    result 


CHEMISTRY   OF   THE   EARTH     85 

enormous  variations  are  found,  and  when  a 
number  of  various  claimants  for  chemical 
union  are  present,  as  for  example,  in  a 
world  cooling  down  in  space,  the  varying 
amounts  of  different  chemical  compounds 
formed  and  their  variety  will  depend  on  the 
amounts  and  affinities  of  the  constituents 
present. 

In  these  questions  of  affinity  two  factors 
come  in,  there  is  always  an  affinity  to  be  over- 
come, as  well  as  the  one  which  is  satisfied  as 
the  result  of  the  chemical  action  between 
the  two  substances  or  elements.  It  is  rarely 
that  the  atoms  of  an  element  exist  singly  in 
nature.  When  such  elemental  atoms  cannot 
find  other  dissimilar  atoms  to  unite  with 
they  unite  with  each  other,  usually  in  pairs. 
These  pairs  must  be  sundered  on  both  sides 
before  union  of  the  two  different  kinds  of 
element  can  take  place.  For  example,  it  is 
not  really  two  atoms  of  hydrogen  and  one 
atom  of  oxygen  that  unite  to  form  a  molecule 
of  water.  But  two  molecules  of  hydrogen, 
each  containing  two  atoms  of  that  element, 
and  one  molecule  of  oxygen,  likewise  con- 
taining two  atoms  of  oxygen,  have  to  be 
severed  first,  and  then,  when  freedom  has 
been  obtained,  each  atom  of  oxygen  becomes 
attached  to  two  atoms  of  hydrogen,  so  that 


86     ORIGIN  AND  NATURE  OF  LIFE 

two  separate  molecules  of  water  are  formed. 
This  is  the  way  the  matter  must  be  put  to 
render  it  readily  understandable.  As  a  matter 
of  fact,  for  any  such  chemical  reaction,  thous- 
ands of  millions  of  molecules  of  hydrogen 
and  oxygen  are  ruptured  simultaneously,  but 
the  above  statement  represents  the  propor- 
tions in  which  the  molecules  are  concerned. 

The  second  main  characteristic  of  valency 
is  also  illustrated  in  the  above  example.  It 
is  to  be  noticed  that  two  atoms  of  hydrogen 
are  required  to  each  atom  of  oxygen.  The 
atom  of  oxygen  has  double  the  valency  of  the 
atom  of  hydrogen,  in  this  reaction.  In  the 
formation  of  ammonia,  as  union  of  one  atom 
of  nitrogen  with  three  of  hydrogen  occurs,  the 
nitrogen  atom  has  treble  the  value  of  the 
hydrogen  atom,  and,  in  the  other  example 
given  above  of  marsh  gas,  the  carbon  atom 
possesses  four  times  the  valency  of  hydro- 
gen. 

A  number  of  elements  exist  which  possess 
the  same  valency  as  hydrogen,  such  as 
chlorine  mentioned  above,  which  unites  atom 
for  atom  with  hydrogen  to  form  hydro- 
chloric acid,  and  the  same  is  true  of  the 
other  members  of  the  chlorine  family,  namely, 
fluorine,  bromine  and  iodine,  which  similarly 
unite  atom  for  atom  with  hydrogen  to  form 


CHEMISTRY   OF   THE    EARTH     87 

hydrofluoric,  hydrobromic  and  hydriodic  acids 
respectively. 

Proceeding  on  the  axiomatic  basis  that 
things  which  are  equal  to  the  same  are  equal 
to  one  another,  if  it  is  found  that  other 
elements  unite  with  chlorine,  one  to  one, 
such,  for  example,  as  the  alkali  metals, 
lithium,  sodium  and  potassium,  which  form 
lithium  chloride,  sodium  chloride,  and  potas- 
sium chloride  respectively,  then  it  is  possible 
to  say  that  the  valency  of  these  three  metals 
is  the  same  as  that  of  hydrogen.  It  is 
necessary  to  follow  this  deductive  step 
closely,  for  much  depends  on  it.  The  argument 
is  that  two  atoms,  viz.,  one  of  hydrogen  and 
one  of  chlorine,  unite  to  form  a  compound 
containing  one  atom  of  each,  their  valencies 
are  accordingly  equal,  now  hydrogen  (the 
measure  of  valency)  cannot  be  united  with 
lithium,  sodium  and  potassium,  since  it 
possesses  practically  no  affinity,  or  chemical 
avidity,  for  them,  but  chlorine  unites  with 
the  atoms  of  these  elements  in  the  ratio 
of  equality  to  form  molecules  known  as 
chlorides,  which  possess  one  atom  each  of 
chlorine  and  of  one  of  these  elements.  The 
inference  is  that  lithium,  sodium,  and  potas- 
sium are  equal  in  valency  with  hydrogen 
and  chlorine.    Experimentation  on  this  basis 


88     ORIGIN  AND  NATURE  OF  LIFE 

completes  gradually  the  list  of  elements  all 
equal  to  hydrogen  and  to  one  another  in 
valency,  and  as  no  elements  in  nature  are 
found  of  a  lower  order  of  valency,  such,  for 
example,  as  would  unite  two  of  their  atoms 
to  one  of  hydrogen  or  any  others  of  the 
above  group,  it  becomes  obvious  that  the 
valency  possessed  by  hydrogen,  and  its 
equals,  is  the  minimal  valency.  These  ele- 
ments are  accordingly  called  monads,  or 
univalent  elements. 

The  next  order  of  valency  amongst  the 
elements  is  such  that  an  element  belonging 
to  this  group  possesses  double  the  affinity 
of  the  monad,  and  these  elements  are  called 
dyads  or  divalent  elements.  This  is  a  large 
group  of  which  oxygen  may  be  taken  as 
the  type.  As  stated  above,  water  shows 
the  divalent  nature  of  oxygen,  for  one  atom 
of  oxygen  is  united  in  it  to  two  atoms  of 
hydrogen.  The  same  runs  through  all  the 
oxides  of  the  univalent  metals  mentioned 
above  for  two  of  each  of  these  unite  with  one 
of  oxygen,  when  they  combine  spontaneously 
with  oxygen  to  form  oxides.  Compounds  are 
also  known  in  which,  instead  of  two  atoms  of 
each  alkali  metal,  one  atom  of  the  univalent 
metal  and  one  of  hydrogen  unite  with  the 
divalent  oxygen  to  form  compounds  called 


CHEMISTRY   OF   THE   EARTH     89 

hydrates,  which  are  thus  compounds  contain- 
ing three  elements.  For  example,  that  well- 
known  substance  called  sodium  hydrate, 
chemically,  or  caustic  soda,  commercially, 
of  which  our  country  manufactures  millions 
of  tons  annually  for  soap-making  and  many 
hundreds  of  industrial  uses,  is  very  simply 
composed  of  an  atom  of  divalent  oxygen 
united  to  one  atom  each  of  univalent  sodium 
and  univalent  hydrogen.  It  might  be 
regarded  as  water  with  one  of  the  two  hydro- 
gen atoms  replaced  by  the  metal  sodium, 
which  possesses  a  stronger  affinity  for  the 
position.  It  is  for  this  reason  that  caustic 
soda  is  called  a  hydrate,  and  it  may  be  actually 
made  by  throwing  a  small  piece  of  metallic 
sodium  on  water  when  the  water  is  decom- 
posed, hydrogen  discharged,  and  set  fire  to 
by  the  heat  energy  evolved.  This  hydrogen 
burns  with  the  oxygen,  re-forming  water, 
and  the  sodium  present  colours  the  flame 
that  intense  yellow,  which  gives  the 
sodium  spectrum  referred  to  in  the  previous 
chapter. 

Just  in  the  same  way  as  hydrogen  was  used 
for  measuring  out  the  univalent  group, 
the  oxygen  atom  may  be  used  for  measuring 
out  the  divalent  group.  For  example,  the 
metals  calcium  and  copper  each  unite  atom 


90     ORIGIN  AND  NATURE  OF  LIFE 

for  atom  with  oxygen  to  form  compounds 
containing  only  two  atoms,  and  this  leads  the 
chemist  to  suspect  that  these  must  be  divalent 
elements.  Now,  on  forming  compounds  of 
these  with  chlorine  the  suspicion  is  confirmed, 
for  each  unites  with  the  chlorine  under 
ordinary  conditions  to  form  compounds  in 
which  two  atoms  of  chlorine  are  united 
with  one  of  the  calcium  or  copper.  In  the 
same  way  elements  which  act  as  triads, 
tetrads,  pentads,  and  even  hexads  can  be 
identified. 

In  chemical  interchanges  and  variations 
from  compound  to  compound,  it  may  generally 
be  said  that  where  chemical  affinities  permit 
of  it,  one  monad  can  replace  another,  or  a 
dyad  atom  may  be  replaced  by  two  of  a 
monad,  or  by  one  atom  each  of  two  different 
monads,  and  so  on  ;  but  circumstances  often 
arise  which  make  this  rule  inapplicable.  For 
example,  where  a  dyad  is  acting  as  a  connecting 
link  between  two  groups  of  atoms  it  cannot 
be  replaced  by  two  monads  without  the 
compound  splitting  into  two  smaller  com- 
pounds to  each  of  which  one  of  the  monads 
attaches  itself. 

Another  complication  arises  because  of 
the  tendency  possessed  by  elements  with 
higher    valencies    to    lower    their    apparent 


CHEMISTRY    OF    THE    EARTH     91 

valency  by  a  kind  of  internal  union  of  certain 
of  their  valencies,  much  in  the  same  way 
as  it  was  pointed  out  above  that  two  atoms 
of  hydrogen  unite  to  satisfy  each  other  in  the 
absence  of  more  powerful  attractions  of  other 
elements.  For  example,  nitrogen  and  phos- 
phorus are  pentavalent  atoms  which  possess 
five  dynamic  centres  of  energy  capable  of 
forming  combinations.  But  in  the  majority 
of  their  compounds,  two  of  these  dynamic 
centres  set  up  internal  attractions  or  pertur- 
bations in  regard  to  each  other,  as  a  result 
of  this  the  nitrogen  or  phosphorus  is  left  with 
three  free  dynamic  centres,  and  possesses  an 
apparent  valency  of  a  trivalent  element. 
A  similar  effect  is  often  seen  between 
two  atoms  of  a  polyvalent  element.  For 
example,  two  carbon  atoms  may  come 
into  energy  relationship  by  two  of  their 
dynamic  centres  or  valencies  and,  as  a  result, 
although  each  carbon  atom  possesses  four 
valent  positions,  the  two  atoms  after  this 
union  of  themselves  have  only  two  centres 
left  upon  each  atom,  or  four  in  all,  and  a  com- 
pound is  formed  of  two  atoms  of  carbon  with 
four  of  hydrogen,  the  well-known  olefiant 
gas. 

In  settling  valencies,  the  greatest  caution 
has  accordingly  to  be  observed  by  the  chemist. 


92     ORIGIN  AND  NATURE  OF  LIFE 

He  deals,  if  possible,  especially  in  studying 
the  elements  with  higher  valencies,  only  with 
compounds  of  simple  type  containing  if 
possible  only  one  atom  in  the  molecule 
of  the  polyvalent  element,  and  he  directs  his 
attention  to  the  compound  which  he  can 
prepare  with  the  highest  valency  exhibited, 
and  in  that  compound  univalent  elements 
so  far  as  possible  occupying  the  available 
dynamic  centres  of  the  polyvalent  element. 
In  his  quest  he  is  assisted  by  many  experi- 
mental touchstones  which  need  not  here  be 
considered  in  detail. 

Carbon  is  that  one  of  all  the  elements  that 
concerns  us  most  intimately  because  its  high 
valency  and  its  unparalleled  power  of  uniting 
with  itself  as  well  as  with  other  elements, 
enables  it  to  build  up  single  molecules  con- 
taining very  large  numbers  of  atoms,  and  such 
molecules  form  the  basis  for  framing  the 
structure  of  living  organisms.  Without  these 
two  properties  of  the  carbon  atom,  life,  at 
least  as  it  is  known  upon  the  earth,  would  be 
impossible,  and  accordingly  it  may  be  well 
to  describe  in  outline,  as  simply  as  possible, 
the  proof  that  carbon  is  a  tetrad  element, 
and  the  results  in  molecule  building  which 
rest  ultimately  upon  its  remarkable  power  of 
self-union. 


CHEMISTRY  OF   THE   EARTH     93 

It  has  been  said  above  that  two  carbon 
atoms  can  unite  and  so  partially  saturate 
each  other,  and  leave  over  four  positions 
which  can  be  occupied  by  four  hydrogen 
atoms  so  giving  a  compound  of  two  carbon 
and  four  hydrogen  atoms.  But  how,  it  may 
be  asked,  is  it  known  that  this  compound  does 
not  consist  of  one  carbon  atom  and  two 
hydrogen  atoms,  the  relative  proportion  of 
carbon  and  hydrogen  would  be  just  the  same, 
and  then  carbon  would  be  a  dyad,  since  it 
unites  with  two  hydrogen  atoms  ?  The 
proof  lies  in  the  weight  of  the  gas  formed 
relatively  to  that  of  hydrogen,  when  equal 
volumes  are  weighed.  All  gases  contain  in 
equal  volumes,  under  like  conditions,  the  same 
number  of  molecules,  as  is  proven  by  many 
concordant  facts  in  physics  and  chemistry. 
This  gives  a  criterion,  for  it  is  obvious  that, 
if  in  one  case  the  gas  molecule  contained  one 
atom  of  carbon  and  two  of  hydrogen  and  in 
the  other,  two  atoms  of  carbon  and  four  of 
hydrogen  (since  the  weight  of  the  volume  of 
gas  is  the  united  weight  of  all  the  molecules), 
then  in  the  second  case  the  gas  must  be  twice 
as  heavy  as  the  first.  The  latter  result  is  the 
one  found  experimentally,  the  density,  or 
weight  per  equal  volume,  of  the  gas  compared 
to  hydrogen  shows  that  its  molecule  must 


94     ORIGIN  AND  NATURE  OF  LIFE 

be  made  up  of  two  atoms  of  carbon  and 
four  of  hydrogen.  So  such  an  apparent 
exception  is  accounted  for,  as  can  all  similar 
cases. 

Coming  now  to  direct  evidence  as  to  the 
tetra-valeat  nature  of  the  carbon  atom,  it 
is  found  that  the  clearest  proof  is  given  by  a 
series  of  compounds  between  carbon,  hydrogen 
and  chlorine,  in  which  there  exists  only  one 
atom  of  carbon  in  the  molecule  of  each  com- 
pound, and  the  hydrogen  can  be  replaced  in 
four  stages  by  the  chlorine  in  such  a  way 
that  it  is  demonstrated  that  there  are  four 
atoms  of  hydrogen  in  the  compound  which 
has  most  hydrogen  and  four  atoms  of  chlorine 
in  that  which  has  most  chlorine. 

The  compounds  can  be  represented  by  the 
following  scheme,  but  it  must  most  carefully 
be  remembered  that  the  atoms  are  not  really 
linked  or  hooked  together,  but  probably  many 
hundreds  of  times  their  own  dimensions 
removed  from  one  another.  It  is  the  energy 
properties  of  the  carbon  atom  which  in  some 
unknown  way  enable  it  to  remain  in  balanced 
equipoise  with  four  of  these  univalent  atoms, 
and  never  with  more  or  less  than  four 
of  them.  In  the  formulae,  or  symbols,  C 
stands  for  carbon,  H  for  hydrogen,  and  CI  for 
chlorine  : — 


CHEN 

list: 

EtY 

OF 

THE   EARTH     95 

H 

1 

Cl 

i 

Cl 

i 

H-C-H 

i 

H 

I 

-C- 

i 

-H 

Cl-C-H 

i 

i 
H 

1 
H 

1 
H 

(1) 

Cl 

i 

(2) 

Cl 

i 

(3) 

CI 

i 
-c- 

1 

H 

(4) 

-Cl 

Cl- 

1 
-C- 

1 
Cl 

(5) 

-Cl 

All  the  members  of  this  series  are  well- 
known  bodies.  The  first  is  called  chemically 
methane,  or  from  its  natural  occurrence, 
marsh  gas.  The  second  is  called  methyl 
chloride,  the  group  (CH3)  united  to  the  single 
atom  of  chlorine  forming  a  characteristic 
group  in  organic  chemistry  which  goes  into 
and  comes  out  of  compounds  as  if  it  were  a 
single  univalent  atom ;  such  a  group  is 
called  an  organic  radical.  The  third  member 
with  two  chlorine  atoms  is  called  di-chlor- 
methane,  for  obvious  reasons.  The  fourth 
member  with  three  chlorine  atoms  is  the 
well-known  anaesthetic,  chloroform  ;  its  chemi- 
cal name  is  tri-chlor-methane.  The  fifth 
member  where  all  the  hydrogen  has  been 


96     ORIGIN  AND  NATURE  OF  LIFE 

replaced  by  chlorine  is  called  carbon -tetra- 
chloride, and  is  an  exceedingly  valuable 
organic  solvent,  especially  for  bodies  of  a 
fatty  nature.  It  has  the  desirable  property 
that  it  is  not  very  readily  inflammable, 
as  ether,  benzene,  and  many  other  organic 
solvents  are. 

All  these  bodies  are  formed  in  varying 
quantities  when  the  two  gases  methane  and 
chlorine  act  upon  one  another,  and  by  appro- 
priate means  can  be  separated  and  identified. 
Once  this  has  been  achieved,  large  quantities 
can  be  manufactured  by  more  appropriate 
methods,  and  their  chemical  nature  examined. 
The  densities  of  their  vapours  compared  with 
hydrogen  show  that  only  one  carbon  atom 
is  present,  and  when  they  are  burnt  or 
combusted  with  oxygen,  and  the  percentages 
of  carbon,  hydrogen,  and  chlorine  estimated 
by  analysis,  the  numbers  of  atoms  present 
in  each  case  can  be  calculated,  on  the  basis  of 
the  known  atomic  weights  of  the  elements  as 
settled  by  the  concordant  analyses  of  many 
other  simple  inorganic  compounds.  When 
this  has  been  done  the  only  formulae  which  will 
fit  the  compounds  are  those  set  out  above. 

It  follows  from  this  that  the  carbon  atom 
is  a  collection  of  energy  forms,  or  electrons, 
possessing  such  dynamic  properties  that  it 


CHEMISTRY   OF   THE   EARTH     97 

is  in  equilibrium  with  four  univalent  atoms 
or  their  equivalents.  Such  equivalents  may 
be  legion,  and  so  long  as  the  carbon  atom 
has  four  centres  of  activity  satisfied  by  four 
such  centres  outside  itself,  it  is  saturated  and 
in  equilibrium.  Failing  outside  attractions 
two  of  the  four  may  enter  into  interplay  with 
each  other,  and,  such  a  carbon  atom  is  then 
spoken  of  as  an  unsaturated  carbon  atom. 
The  name  is  in  reality  a  misnomer,  for  it  is 
saturated,  except  when  something  of  superior 
affinity  presents  itself,  and  then  the  two 
dynamic  centres  which  were  previously  play- 
ing upon  each  other,  enter  into  relationship 
with  the  new  body.  For  example,  the  com- 
pound called  carbon-monoxide  which  forms 
the  poisonous  constituent  of  coal  gas,  or  in  the 
gas  from  a  charcoal  fire,  or  brick-kiln  or  lime- 
kiln, is  such  an  unsaturated  compound  with 
one  tetrad  atom  of  carbon  united  to  the 
dyad  atom  of  oxygen,  and  the  other  two 
affinities  of  the  carbon  atom  more  feebly 
satisfying  each  other  by  self  interplay  of 
energy.  If  now,  this  gas  be  mixed  with 
chlorine  gas  the  chlorine  interacts  spontan- 
eously with  the  two  carbon  affinities  which 
were  previously  interacting  with  each  other, 
and  each  of  these  now  comes  into  dynamic 
interplay  with  a  chlorine  atom.     As  a  result, 


98     ORIGIN  AND  NATURE  OF  LIFE 

there  is  formed  the  substance  called  carbonyl 
chloride,  of  which  the  molecule  contains  one 
carbon  atom,  one  oxygen  atom,  and  two 
chlorine  atoms.  If,  more  simply,  the  carbon 
monoxide  is  burnt  in  the  air,  one  extra  atom 
of  oxygen  enters  into  relationship  to  the  two 
affinities  of  the  carbon,  and  the  very  common 
substance  carbon-dioxide  is  formed.  This 
body  is  present  in  minute  amounts  in  the  air, 
and  it  is  of  interest  to  note  here  that  from  it 
the  green  plant  is  able  when  it  is  aided  by 
the  energy  of  the  sunlight,  to  build  up  those 
organic  substances  of  complex  nature  found 
in  living  plants. 

It  is  a  curious  fact  that  all  life  on  the  earth 
should  depend  upon  two  simple  factors,  (1)  the 
presence  of  a  mere  trace,  lying  at  the  level  of 
only  between  three  and  four  parts  per  10,000, 
of  this  gas  in  the  air,  and  (2)  the  natural 
power  of  the  carbon  atom  contained  in  the 
carbon-dioxide,  of  entering  into  energy  rela- 
tionships with  fellow  carbon  atoms.  Given 
these  conditions,  a  suitable  form  of  energy, 
and  a  suitable  machine  or  transformer  for 
that  energy  capable  of  turning  it  into  chemical 
energy  of  carbon  compounds,  and  it  follows 
that  all  the  complex  organic  constituents  which 
form  the  basis  of  life  not  only  can,  but  musU 
arise. 


CHEMISTRY   OF   THE    EARTH     99 

The  energy-transformer  is  the  green  plant- 
cell  aided  by  the  green  colouring  matter, 
called  chlorophyll,  which  it  contains.  The 
energy  which  is  converted  into  chemical 
energy  of  organic  compounds  is  that  of  the 
sunlight,  and  the  simple  forms  of  matter 
which  undergo  transformation,  are  the  carbon- 
dioxide  above  mentioned,  water,  and  simple 
inorganic  salts  containing  compounds  of 
nitrogen  such  as  ammonia  or  nitric  acid,  and 
a  few  common  elements  of  inorganic  nature 
as  simple  salts  taken  up  from  the  soil.  In  this 
natural  laboratory  of  the  plant,  energy  is 
introduced  into  these  simple  forms,  their 
chemical  constitution  is  thereby  changed, 
and  they  become  storehouses  of  energy  in 
chemical  form.  These  organic  forms  of 
matter,  so  elaborated,  form  the  food  of 
animals  by  whose  activities  they  are  finally 
broken  down  into  their  original  forms,  or  others 
closely  resembling  them,  and  so  the  cycle 
is  completed.  All  energy  of  all  living  things 
is  dependent  upon  green  plants,  and  they 
in  turn  are  dependent  upon  the  sunlight. 

As  will  be  pointed  out  later,  all  commence- 
ments of  life  now  or  earlier  must  have  de- 
pended on  sunlight,  but  it  is  highly  improbable 
that  the  exceedingly  complex  green  cell  of 
the  plant   formed  the   starting  point.     Life 


100    ORIGIN  AND  NATURE  OF  LIFE 

had  to  surge  a  long  way  up  from  the  depths 
before  a  green  plant  cell  came  into  being. 
Once  such  a  cell  was  formed  it  would  retain 
its  stability  under  suitable  environment,  and 
form  a  new  point  of  departure,  but  there 
exists  a  wide  hiatus  between  inorganic  mole- 
cules and  the  green  plant  cell  which  we  must 
bridge  as  best  we  may  before  we  begin  to 
understand  the  origin  of  life. 

The  present  is,  however,  the  place  to 
describe  briefly  that  peculiar  property  pos- 
sessed by  the  carbon  atom  of  uniting  with  its 
fellow  atoms,  which  is  there  ready  to  yield 
material  for  the  physico-chemical  structures 
of  life  so  soon  as  the  energy  transformer  has 
been  evolved.  In  later  chapters,  the  interval 
will  be  dealt  with  lying  between  inorganic 
molecules  and  the  green  plant  cell  and  its 
organic  products. 

It  is  only  a  chemical  atom  possessing  a  high 
valency  which  is  capable  of  uniting  in  this 
way  so  as  to  form  a  very  large  molecule,  apart 
from  the  quite  different  mode  of  formation 
of  bodies  called  colloids  to  be  dealt  with  in 
the  next  chapter.  Colloids,  it  will  be  found, 
are  formed  by  molecular  unions  in  which  each 
molecule  behaves  as  a  single  atom,  just  as 
previously  in  forming  the  atoms  the  electrons 
united.     In    the    colloid,    each    constituent 


CHEMISTRY   OF   THE   EARTH     101 

molecule  of  an  aggregate  of  molecules,  is 
completely  saturated,  and  there  is  no  atomic 
affinity  between  the  molecules.  This  is  entirely 
different  from  the  point  being  described  here 
of  the  building  up  of  a  giant  single  molecule 
by  the  aid  of  the  carbon  atom.  For  this 
latter  purpose,  the  central  or  building  atom 
must  have  a  high  valency,  and  yet  the  valency 
must  not  exceed  a  certain  limit.  Univalent 
atoms  obviously  cannot  build  up  a  large 
molecule  by  themselves,  because  when  two 
unite  no  more  atomic  affinities  are  left  over. 
The  only  apparent  exceptions  are  where  such 
a  binary  compound  of  two  univalent  atoms 
unites  with  water  to  form  crystals,  or  where 
two  such  binary  compounds  unite  together 
in  a  feeble  way.  But  this  is  not  atomic  union 
at  all.  It  belongs  to  the  molecular  com- 
binations described  in  the  next  chapter. 

If  we  next  consider  a  divalent  element 
attempting  to  unite  atomically  to  form  large 
groups,  it  becomes  obvious  that  to  form  any 
dynamic  concatenation,  or  constellation,  each 
atom  will  have  to  unite  with  two  others,  and 
hence  no  affinities  are  left  over  to  enter  into 
similar  relations  with  the  other  dissimilar 
elements  necessary  to  make  up  the  molecule. 
For  example,  a  large  number  of  oxygen  atoms 
might  begin  to  bind  together  in  interplay, 


102    ORIGIN  AND  NATURE  OF  LIFE 

but  both  affinities  would  be  involved  in 
holding  them  in  such  relations,  and  so  none 
would  be  left  over  for  attaching  any  other 
element.  Hence  the  whole  group  could  be 
oxygen,  and  oxygen  only ;  no  compound  could 
be  formed. 

The  lowest  valency  at  which  such  dynamic 
grouping  of  a  considerable  number  of  atoms 
could  occur  is  that  of  the  trivalent  atom, 
where  after  the  unions  of  the  trivalent  atoms 
one  valency  would  be  left  upon  each  for  union 
with  the  dissimilar  atoms  or  groups.  Although 
this  is  feasible  there  are  objections  from  the 
point  of  view  of  stability  of  the  system, 
for  while  in  process  of  building  up  in  the 
tetrad  grouping  there  are  two  affinities  left 
over  on  each  atom  which  can  interplay  with 
each  other  and  hold  each  other  balanced  in 
equilibrium,  until  other  atoms  or  atomic 
groups  of  a  dissimilar  character  present 
themselves  ;  in  the  case  of  the  triad,  only 
one  unbalanced  activity,  or  valency,  is  left 
over  on  each  atom,  and  this  is  an  exceedingly 
unstable  situation,  so  that  the  system  breaks 
up.  Also  it  is  questionable  whether  true 
trivalent  atoms  exist  at  all  in  nature  because 
they  are  themselves  so  unstable.  The  elements 
of  the  phosphorus  group,  namely,  nitrogen, 
phosphorus,    arsenic,    and   antimony,    which 


CHEMISTRY   OF   THE   EARTH     103 

appear  to  be  triads,  are  really  pentads  which 
have  become  facultative  triads  by  self- 
saturation  of  two  of  the  active  centres.  If 
such  elements  united  to  form  a  large  group, 
as  the  element  carbon  does,  there  would  be 
this  additional  element  of  instability,  in  that 
every  member  of  the  group  was  unsaturated, 
in  addition  to  the  union  of  the  similar  elements 
to  one  another.  It  is  thus  seen  that  the 
elements  of  which  the  valency  is  represented 
by  odd  numbers  are  not  suited  for  taking  on 
central  roles  in  large  groupings  of  atoms 
into  a  single  giant  molecule. 

When  the  valency  of  a  hexad  is  reached, 
as  has  been  claimed  to  be  the  case  in  the  iron 
group,  the  atom  itself  reaches  nearly  the  limit 
of  internal  stability,  and  is  just  able,  in  single 
or  dual  atomic  groupings,  to  unite  with  other 
dissimilar  atoms,  but  any  higher  interaction 
between  the  similar  hexad  atoms  than  two 
joined  together  is  never  found.  It  is  indeed 
a  matter  of  doubt  whether  hexad  elements 
exist.  The  energetics  of  such  forms  of 
atomic  matter  at  the  present  state  of  our 
knowledge  are  but  little  known,  and  the 
valency  theory  gets  into  difficulties  in  explain- 
ing them.  It  becomes  clear,  therefore,  by 
such  processes  of  exclusion  that  the  type  of 
element  in  which  the  electrons  are  so  arranged 


104   ORIGIN  AND  NATURE  OF  LIFE 

and  balanced,  that  the  atom  possesses  the 
power  of  balancing  in  stable  equilibrium  with 
four  monad  atoms  or  their  equivalent,  is  that 
form  alone  which  can  build  up  huge  mono- 
molecules. 

This  is  what  is  found  actually  to  occur  in 
nature.  Carbon,  which  is  the  most  typical 
tetrad,  shows  the  property  in  highest  degree, 
the  only  other  element  approaching  near  to  it 
being  silicon,  which  is  also  a  tetrad. 


CHAPTER   V 

BUILDING  MATERIALS   FOR  LIVING  MATTER 

As  a  result  of  this  wonderful  property  of 
self-equilibration  of  dynamic  properties  in  the 
carbon  atom  single  molecules  are  capable  of 
forming,  which  contain  some  hundreds  of 
carbon  atoms,  and  often  in  the  life  processes 
such  molecules  are  built  up  with  molecular 
weights  running  into  several  thousands,  while 
inorganic  mono-molecules  only  run  into  a 
few  hundreds  in  their  molecular  weight,  and 
usually  average  less  than  that  level. 

If  the  carbon  atoms  are  represented  in  the 
usual  statical  way  by  formulae  so  as  to  get 


BUILDING  OF  LIVING  MATTER    105 

a  model  by  which  to  visualize  the  process, 
the  manner  in  which  this  occurs  can  readily 
be  shown.  But  it  is  ever  to  be  remembered 
that  because  a  model,  or  formula,  can  be  set 
down  upon  paper  it  does  not  follow  that  the 
reaction  will  occur.  The  occurrence  or  non- 
occurrence of  the  reaction  depends  upon 
the  balance  of  energies  within  the  radius  of 
action  of  each  atom,  which  behaves  much  like 
an  infinitely  small  planet,  or  sun,  in  relation- 
ship to  other  planets  in  the  molecular  micro- 
cosm. Remembering  this  carefully,  we  may 
illustrate  a  scheme  whereby  molecules  such  as 
exist  in  living  cells,  may  be  built  up. 

It  is  a  curious  fact  in  nature  that  there 
seems  to  be  a  position  of  greater  stability 
when  groups  of  six  carbon  atoms  unite  in 
little  galaxies  or  concatenations.  Other 
groups  than  those  of  six  do  exist,  but  they  are 
not  so  stable  nor  so  easily  formed  under  natural 
conditions  such  as  obtain  in  living  organisms. 
Although  such  groups  of  less,  or  occasionally 
more,  than  six  carbon  atoms  are  formed 
naturally  by  life  processes,  by  far  the  greater 
portion  of  the  substance  of  living  organisms 
is  built  up  of  six  carbon  groups  and  multiples 
of  these. 

There  are  two  main  types  of  six-grouped 
carbon    atoms    which    the    organic    chemist 


106    ORIGIN  AND  NATURE  OF  LIFE 

represents  conventionally  by  open  and  closed 
chains  of  atoms,  and  these  he  calls  fatty  or 
aliphatic  groups,  and  benzene  or  aromatic 
groups,  respectively.  Representing  the  carbon 
atom  by  the  letter  C  and  its  four  dynamic 
affinities  by  short  lines,  which,  when  they  run 
from  one  carbon  atom  to  another,  show  centres 
in  interplay  with  one  another,  and  when  they 
are  attached  at  one  end  only  show  free  centres 
open  to  combine  with  other  atomic  groupings 
or  atoms,  then  the  two  types  of  six-grouped 
carbon  atoms  may  be  illustrated  by  these  two 
formulae  : — 

Aliphatic.  Aromatic. 

II 
C 

/    \ 

I     I     I     I     I     I  =c        c= 

-C-C-C-C-C-C-  I  I 

I     I     I     1     I     I  =c       c  = 

\  / 
c 

II 

(1)  (2) 

The  aromatic  group  in  this  simplest  form 
is  very  unstable,  and  becomes  more  stable 
when  each  alternate  interplay  between  the 
carbon  atoms  becomes  doubled,  thus  : — 


BUILDING  OF  LIVING  MATTER    107 

I 

C 
/    % 

-c        c- 

II        I 
-c        c- 

\  s 
c 

I 

(3) 

so  leaving  each  carbon  atom  with  only  one 
free  centre  of  activity. 

Now  these  formulae  do  not  represent  actual 
organic  substances,  but  only  structures  on 
which  molecules  can  be  built  up  ;  none  of 
them  can  exist  unless  the  free  activities  are 
taken  up  by  other  atoms  or  groups  of  atoms. 
Take  the  simplest  case,  that  each  of  the  free 
positions  is  taken  up  by  a  hydrogen  atom  (H). 
Then  the  schemes  represent  actual  existing 
bodies  called  hydrocarbons.  The  third  one 
would  represent  the  molecule  of  the  well- 
known  substance  benzene,  or  benzol,  the  first 
one  a  known  hydrocarbon,  hexane,  and  the 
second  one  a  reduced  benzene  (hexa-hydro- 
benzol). 

Very  many  other  groupings  than  simply 
putting  in  hydrogen  atoms  can  evidently  be 
made,  and  hence  without  any  reduplication 


108    ORIGIN  AND  NATURE  OF  LIFE 

a  large  host  of  organic  compounds  can  be 
made. 

As  an  illustration  of  this,  if  instead  of  two 
of  the  hydrogen  atoms  at  one  of  the  end 
carbons  of  the  formula  (1)  an  oxygen  atom 
(O)  be  put  in,  and  for  one  of  the  hydrogens, 
on  each  of  the  other  carbon  atoms  the  atomic 
group  called  hydroxyl,  consisting  of  an  atom 
of  oxygen  and  one  of  hydrogen  (— O— H), 
which  acts  as  a  monad,  be  introduced,  the 
formula  becomes  : — 


H     H 

i        i 

H     H     H     H 

i        i        i        i 

1        1 
C-C- 

1        1 

I        I        l        I 

-c-c-c-c 

1     1     1 

H-C-C-C-C-C-C=0 

I        I        I        I        I 
OH  OH  OH  OH  OH 

and  this  is  the  formula  of  the  simplest  sugar 
known  to  us.  Next,  if  two  such  whole  big 
molecules  as  the  one  we  have  just  developed, 
are  united  by  setting  free  one  of  the  places 
occupied  by  a  H  in  one,  and  one  of  the 
places  occupied  by  a  HO  in  the  other,  then 
very  simply  a  reduplicated  molecule  is  formed, 
while  the  H  set  free  from  the  one  and  the  H  O 
from  the  other  unite  to  form  a  molecule  of 
water  H  —  O  —  H.  The  sugar  so  formed  would 
be  a  disaccharide  similar  to  cane  sugar,  or 
the  sugar  found  in  milk. 


BUILDING  OF  LIVING  MATTER    109 

But  this  reduplication  can  evidently  go  on 
so  long  as  energy  conditions  in  the  reduplicated 
molecule  will  allow  of  it.  On  paper  a  thousand 
such  reduplications  could  be  set  down  easily, 
and  so  theoretically  a  molecule  as  huge  as 
a  world  could  be  built  up,  but  such  a  structure 
has,  in  actual  fact,  a  limit  at  which  it  breaks 
down  on  account  of  instability.  The  exact 
limit  at  which  instability  stops  the  process 
is  unknown  to  us,  but  this  is  the  simple  way 
in  which  nature  builds  up  starches  in  living 
plants.  Such  starches  possess  at  least  thirty 
to  forty  such  groups,  so  simply  joined  together. 
This  is  a  good  example  of  how  this  step 
in  the  process  of  evolution  towards  life  builds 
up  molecular  structure,  and  it  may  be  premised 
here  that  such  structural  change  is  accom- 
panied by  great  changes  in  the  energy  pheno- 
mena of  the  matter  forming  the  molecule. 

There  are  three  great  divisions  of  the 
organic  bodies  built  up  by  living  plants 
and  animals,  called  carbohydrates,  fats,  and 
proteins,  respectively.  These  are  the  com- 
monest, and  build  up  the  great  bulk  of  the 
living  organisms.  In  addition  to  them  there 
are  other  indispensable  things,  as  will  be 
seen  later.  It  will,  however,  be  sufficient  here, 
if  we  gain  some  idea  of  how  these  three  great 
classes  are  made  up. 


110    ORIGIN  AND  NATURE  OF  LIFE 

An  outline  has  been  given  above  of  the 
relationships  of  the  sugars  and  starches. 
These  together  form  the  carbohydrates,  those 
of  the  fats  and  proteins  may  now  be  considered 
so  far  as  they  come  within  our  line  of  thought. 

The  fats  of  living  cells  consist  of  one  group 
called  glycerine,  which  behaves  as  a  trivalent 
base  united  to  three  huge  groups  of  a  uni- 
valent or  monad  acid.  The  glycerine  is 
simply  a  three  carbon  chain,  in  which  each 
carbon  atom  is  united  to  a  hydrogen  atom 
and  a  hydroxyl  group  (HO),  thus : — 

H     H     H 

I        I        I 
H-C-C-C-H 

!       I       I 
OH  OH  OH 

(Glycerine) 

when  the  fat  is  formed  in  nature,  each  OH 
group  is  replaced  by  a  molecule  of  the  fatty 
acid.  In  this  process  a  hydrogen  atom  is 
set  free  to  unite  with  the  HO  from  the  glycerine 
to  form  water,  much  as  the  reduplication  of 
the  sugar  molecules  to  form  water  was  seen 
to  occur  above.  So  we  have  now  only  to 
elucidate  the  nature  of  this  fatty  acid  which  is 
to  combine  with  the  glycerine.  If  the  formula 
(1)  be  written  down  again,  with  hydrogen 


BUILDING  OF  LIVING  MATTER    111 

atoms  in  all  the  available  spaces  of  the 
carbon  affinities  except  those  of  the  atom  at 
the  end  of  the  chain,  where,  instead,  an  oxygen 
atom  and  an  hydroxyl  group  are  placed, 
then  the  formula  of  a  fatty  acid  is  obtained 
thus : — 

H     H     H     H     H 

I       I       I       I       I 
H-C-C-C-C-C-C=0 
I        I        I        I        I        I 
H     H     H     H     H     OH 

It  is  the  group  represented  on  the  right-hand 
side,  with  one  carbon,  one  oxygen  and  one 
hydroxyl,  which  gives  the  acid  properties. 
This  group  is  known  as  the  carboxyl  group, 
and  always  confers  acid  properties  throughout 
the  organic  world. 

Here,  then,  we  have  an  organic  acid, 
and  if  three  such  molecules,  each  losing  the 
H  atom  of  its  acidic  group,  unite  with  the 
glycerine  molecule,  each  replacing  a  HO  group 
in  that  body,  which  unites  with  the  H  atom  to 
form  H  —  O  —  H  then  there  arises  a  fat.  It 
has  only  to  be  remarked  that  the  actual  fatty 
acids  formed  in  nature,  are  usually  three  times 
as  large  as  this  one,  by  the  union  of  three  six- 
carbon  chains,  only  one  of  which  possesses  the 
acid  group.     The  union  may  be  visualized  as 


112    ORIGIN  AND  NATURE  OF  LIFE 

an  end-to-end  affair,  so  that  a  row  of  carbon 
atoms  eighteen  long  instead  of  six,  is  obtained, 
with  the  acid  group  at  one  end.  It  is  obvious 
what  a  huge  molecule  nature  constructs  when 
she  produces  a  fat ;  it  is  also  clear  on  what 
a  simple  basis  it  is  achieved  by  simple  redupli- 
cation between  these  very  simply  constructed, 
large  moleculed,  fatty  acids  and  the  glycerine 
molecule. 

Setting  aside  the  smaller  differences  at  the 
ends  of  the  linkages,  and  where  unions  of  the 
big  groups  occur,  it  is  obvious  that  the  oft- 
repeated  structure  in  the  carbohydrate  is  the 
carbon  atom  united  to  a  hydrogen  and  a 
hydroxyl  group,  while  in  the  fat  it  is  a  carbon 
atom  with  two  hydrogen  atoms.  Nature  is 
always  engaged  building  up  carbohydrate 
into  fat,  because  it  is  a  more  valuable  store- 
house of  energy,  and,  weight  for  weight, 
gives  out  twice  as  much  heat,  or  other  form 
of  energy  to  the  body.  What  is  the  simple 
process  by  which  it  is  accomplished  ?  By 
input  of  energy  a  HO  group  is  taken  away, 
and  a  hydrogen  atom  put  in  its  place. 
This  means  discharge  of  oxygen  and  replace- 
ment by  hydrogen.  The  chemist  calls  such 
a  process  reduction.  Reduction  is  Nature's 
plan  for  building  up  these  organic  bodies, 
and  so  saving  up  energy  for  later  use  "  while 


BUILDING  OF  LIVING  MATTER    113 

the  sun  shines."  Sunlight  energy  is  taken, 
water  broken  up,  its  hydrogen  built  up  with 
the  carbon  of  carbon-dioxide  into  an  organic 
substance.  Then,  on  reversal  of  the  process, 
this  organic  substance  can  be  oxidized  again, 
yielding  once  more  its  hydrogen  as  water,  its 
carbon  as  carbon-dioxide,  and  its  energy  for 
the  life-processes.  The  process  by  which  the 
green  plant  first  builds  up  carbohydrate  may 
be  represented  very  simply ;  if  the  carbon- 
dioxide  from  the  air  passes  into  union  with  the 
water  in  the  plant  juices  there  is  formed 
carbonic  acid,  which  may  be  represented,  thus 

OH 

I  If  now,  sunlight  acts  upon  this 

HO-C=0 

splitting  up  one  of  the  O  H  groups  and 
replacing  it  by  H,  the  oxygen  being  given  off 
by  the  plant  to  the  air,  the  formula  becomes 

H 

I 
HO-C=0 

This  is  formic  acid,  and  contains  the 
characteristic  carbohydrate  grouping,  carbon, 
hydrogen,  and  hydroxyl  united  together. 
When  it  is  again  reduced  and  united  up  with 
others  to  form  a  six  carbon  chain,  a  carbo- 
hydrate is  the  result. 


114    ORIGIN  AND  NATURE  OF  LIFE 

Fat  formation,  as  stated,  is  only  a  con- 
tinuation of  this  reduction  process  with  still 
more  storage  of  energy. 

Now  the  last  group  of  the  three  great 
organic  divisions  is  approached ;  this  is  the 
central  group  in  the  life  structure,  and 
absolutely  indispensable  in  all  living  plants 
and  animals.  It  is  the  very  citadel  structure 
of  the  cell's  life.  The  group  of  the  proteins 
differs  from  fats  and  carbohydrates,  which  only 
contain  carbon,  hydrogen,  and  oxygen,  in 
that  it  also  contains  nitrogen,  and  sometimes 
also  phosphorus,  sulphur,  iron,  and  a  few 
other  common  elements.  Around  these  cen- 
tral proteins  the  carbohydrates  and  fats  and 
all  other  constituents  are  united,  in  the 
manner  to  be  described  in  the  next  chapter, 
to  form  the  living  machine. 

Enormous  complexity  and  differences,  such 
as  would  require  a  large  volume  for  their 
description,  arise  in  the  formation  of  the 
thousands  of  proteins  known  to  the  bio- 
chemist. But  if  detail  be  abandoned  a  very 
simple  picture  of  the  chemical  building  stones 
from  which  the  protein  edifice  is  constructed, 
and  of  the  artifice  by  which  these  are  built  up 
into  the  proteins,  can  easily  be  presented  even 
to  the  non-chemist. 

In  describing  the  constitution  of  the  fats, 


BUILDING  OF  LIVING  MATTER    115 

the  nature  of  the  organic  acid  had  to  be 
mentioned,  and  the  formula  of  one  with  six 
carbon  atoms  was  set  down.  It  was  repres- 
ented by  a  chain  of  carbon  atoms,  united  to 
each  other  by  two  affinity  centres,  and  with 
the  other  centres  satisfied  by  hydrogen 
atoms,  save  in  the  case  of  one  of  the  terminal 
carbon  atoms,  where,  instead,  was  found  the 
acidic  group  in  which  one  hydroxyl  group 
(HO)  and  one  oxygen  atom  (O)  held  the 
available  affinities,  so  giving  the  formula  :— 

H     H     H     H     H  HO 
I       I       I       I        I       I 
H-C-C-C-C-C-C=0 

I        I       I        I       I 
H     H     H     H     H 

This  is  an  acid,  but  if  now  the  substance, 
ammonia,  represented  by  the  formula, 
H-N-H, 

I  be  taken  and  supposed  to  have  lost 

H 
one  of  its  hydrogens,  it  then  acts  as  a  monad 

-N-H, 
group       1  which  can  replace  a  hydrogen 

H 
atom   in   the   above   formula.     This   can   be 
done  experimentally   by  means  which  need 


116   ORIGIN  AND  NATURE  OF  LIFE 

not  here  be  described.  If  it  be  supposed 
that  this  group,  called  amidogen,  takes  the 
place  of  the  hydrogen  atom  at  the  extreme 
left  in  the  formula  of  the  acid  shown  above, 
then  the  formula  becomes  : — 

H     H     H     H     H     H     H 

I       I       I       I       I        I       I       ^ 

N_c-c-c-c-c-c=o 

I     I     I     I     I     I 

H     H     H     H     H     H 

By  means  of  this  quite  simple  formula,  the 
structure  of  the  proteins  can  readily  be 
explained,  and  also  many  of  their  peculiar 
properties  which  enable  them  to  play  their 
part  in  the  phenomena  of  life. 

Ammonia,  as  every  one  knows,  is  a  strong 
base  which  neutralizes  acids,  and  if  it  had 
merely  gone  into  the  acid  group  at  the  other 
end  it  would  simply  have  neutralized  the 
acid.  But  now  the  acid  group  is  there  intact, 
and  at  the  same  time  at  the  other  end  there 
is  a  molecule  introduced,  the  amidogen,  or 
H— N— H,  which  confers  alkaline  or  basic 
properties.  Here,  then,  is  a  new  kind  of 
body,  which  is  acid  in  one  part  and  basic  in 
another,  and  with  neither  property  neutralized. 

The  molecule  has  taken  on  a  kind  of 
chemical  polarity,  or  duality,  like  a  magnet. 


BUILDING  OF  LIVING  MATTER    117 

Such  molecules,  like  tiny  magnetized  iron 
particles,  can  almost  adhere  together. 

This  peculiar  chemical  body  so  evolved  is 
called  an  amino  acid,  and  amino  acids  are 
the  basis  for  all  the  proteins.  There  are  many 
different  types  and  thousands  of  individuals, 
and  these  can  build  up  a  legion  of  protein 
forms.  It  is  most  remarkable  that  here 
also  the  peculiar  property  of  the  carbon 
atom  to  be  most  stable  in  galaxies  of  six 
again  comes  in.  There  are  many  exceptions, 
but  six  is  a  very  favourite  number  of  atoms 
for  the  amino  acids  to  contain,  and  the 
bulk  of  the  mass  of  any  protein  mole- 
cule is  built  up  of  amino  acids  with  six 
carbon  atoms  in  the  molecule,  the  hydrogen 
atoms  represented  in  the  type  formula  shown 
above,  may  be  replaced  by  many  diverse 
groups,  so  swelling  the  host  of  individuals. 
So  long  as  there  is  an  amino  group  and  an 
acid  group  the  remainder  may  be  arranged 
on  many  schemes. 

Sometimes  there  are  two  amino  groups 
instead  of  one  when  the  amino  acid  is  called 
a  di-amino  acid,  also  there  may  sometimes  be 
two  acid  groups.  Some  such  di-amino  groups 
occur  in  all  proteins.  In  the  schematic 
formulae,  these  di-amino  acids  furnish  oppor- 
tunities for  branching  or  side-chains,  so  that 


118   ORIGIN  AND  NATURE  OF  LIFE 

the  formula  instead  of  a  long  simple  chain 
branches  out  in  a  tree-like  way.  The  formula, 
as  has  often  been  insisted  upon,  is  only  a 
visualizing  model,  but  this  property  occurring 
in  the  model,  suggests  that  the  di-amino 
acid,  in  actual  nature,  may  furnish  a  device 
for  changing  the  relationships  in  space  of  the 
huge  growing  protein  molecule  and  rendering 
it  more  stable  than  if  mon-amino  acids  alone 
were  present.  When  di-amino  acids  are 
present  the  giant  molecule  may  remain 
dynamically  stable  up  to  a  higher  level. 

The  mon-amino  and  di-amino  acids  form 
the  building  stones  for  the  construction  of  the 
proteins,  and  the  manner  of  their  doing  so 
is  exceedingly  simple.  Each  one  has  a  basic 
portion,  and  an  acid  portion.  The  acid 
portion  of  the  one  has  chemical  attraction 
for  the  basic  portion  of  the  other,  and  they 
condense  or  unite  just  as  the  two  simple 
sugars  have  been  seen  to  unite  to  form  a 
di-sugar,  and  the  di-sugars  to  unite  to  form 
poly-sugars,  otherwise  called  starches,  or  cellu- 
loses of  the  plants  and  animals. 

If  the  two  letters  A  and  B  be  used  to 
represent  the  changeable  body  part  of  each 
amino-acid  so  uniting,  the  constant  acid  group 
be  represented  by  the  letters  indicating  the 
elements  in  it  as  COOH,  and  the  constant 


BUILDING  OF  LIVING  MATTER    119 

basic  group  similarly,  as  N<^    ,  then  the  union 
can  easily  be  shown  graphically,  thus  : — 


cooh-a-n<^h61oc-b-n/] 


An  acidic  and  basic  end  come  together,  the 
elements  of  a  water  molecule  are  detached, 
as  indicated  by  the  dotted  line,  and  all  the 
rest  forms  a  reduplicated  amino-acid. 

It  is  to  be  noted  next  that  the  whole  larger 
complex  is  still  an  amino-acid,  for  at  one 
end  it  has  still  an  acid  group,  and  at  the  other 
a  basic  group.  The  process  is  analogous  to 
two  magnetized  particles  coming  together 
by  a  north  and  a  -south  pole,  when  the  double 
particle  has  still  a  south  and  a  north  pole, 
and  hence  is  still  a  magnet. 

This  process  can  go  on  so  far  as  molecular 
stability  will  allow,  and  the  products  formed 
are  called  polyamino-acids,  or,  as  the  master- 
worker  at  them,  Emil  Fischer,  suggests,  they 
may  be  called  poly-peptides,  from  their 
resemblance  in  their  properties  to  the  natural 
products  obtained  when  proteins  begin  to  be 
disrupted  by  pepsin  in  digestion  in  the  stomach. 

Fischer  and  his  co-workers  have  made 
artificially    some    hundreds    of    these    poly- 


120    ORIGIN  AND  NATURE  OF  LIFE 

peptides,    and    the    higher    members    closely 
resemble  proteins  in  their  chemical  nature. 

In  the  formation  of  the  true  polypeptide, 
there  is  a  real  chemical  condensation,  with 
true  atomic  union,  and  a  certain  amount  of 
disruptive  force  is  necessary  to  achieve  this. 
In  the  living  cell,  energy  obtained  by  oxidation 
of  other  substances  is  utilized  to  do  this,  and 
in  the  laboratory  the  chemist  does  it  by  having 
present  substances  greedy  for  water.  But 
as  the  molecule  grows  in  size,  it  will  attain  a 
size  at  which  the  reverse  process  of  disrupting 
with  uptake  of  water  tends  to  occur,  and  a 
position  or  degree  of  complexity  will  establish 
itself  at  any  particular  environment  where 
a  balance  holds.  In  the  neighbourhood  of 
this  balancing  point,  a  condition  may  arise 
where  two  polypeptides  come  together,  as 
illustrated,  but  no  atomic  union  can  occur. 
There  is  not  sufficient  energy  to  detach  the 
H  and  O  H  groups  and  condense.  Under 
such  conditions,  the  two  molecules  may  remain 
feebly  held  together  without  true  atomic 
union  as  a  kind  of  dual  molecule.  This 
having  occurred,  the  dual  molecule  still  has 
a  free  acid  group  and  a  free  basic  group, 
and  the  acid  group  can  enter  into  loose 
molecular  relationship  with  the  basic  part  of 
a  third  molecule,  while  the  basic  one  can  play 


BUILDING  OF  LIVING  MATTER    121 

a  similar  part  with  the  acid  part  of  a  fourth 
molecule.  Now  there  are  four  molecules, 
and  still  there  are  free  attachments  for 
more,  for  each  of  the  new  molecules  has  a 
free  active  portion.  If  a  certain  percentage 
of  the  molecules  so  aggregating  are  either 
di-basic  acids,  or  have  two  amino  positions  to 
act  as  a  double  base,  this  system  can  branch 
in  all  directions  in  space. 

Accordingly,  without  true  atomic  union 
between  them,  there  may  be  ten,  twenty, 
thirty,  sixty  molecules  forming  a  great 
aggregate  molecule.  This  is  the  form  in 
which  proteins  occur  in  living  cells,  and  is 
an  example  of  an  organic  colloid. 

A  most  important  point  to  note  here  is 
what  the  chemist  calls  the  "  lability "  or 
"  mobility "  of  such  a  colloid.  Its  strength 
for  the  purposes  of  the  vital  phenomena 
lies  in  its  very  weakness  as  a  chemical  body. 
It  exists  in  a  state  of  the  most  delicate 
balance,  ready  to  play  in  and  out,  and  vibrate 
like  a  piece  of  mechanism,  only  far  more 
delicately,  responding  to  every  change  in  its 
environment.  Its  dimensions  as  an  aggregate, 
and  the  constitution  of  its  parts  depend  on  its 
environment,  and  especially  upon  its  nutrition. 
It  must,  once  it  has  been  constructed,  be 
fed  with  the  proper  pabulum,  nothing  must 


122    ORIGIN  AND  NATURE  OF  LIFE 

be  offered  which  will  unite  too  strongly 
and  lock  up  its  activities.  Material  must 
be  given  to  it  adapted  to  its  uses,  or  upon 
which  it  can  play  and  produce  either  its  own 
building  materials,  or  obtain  energy  for  its 
constant  cyclical  changes. 

There  is,  here,  a  near  approach  to  the 
life  material,  and  it  is  to  be  observed  that 
function  and  activities  alter  and  new 
creative  phenomena  develop  with  developing 
structure. 

These  living  properties  depend  on  labile 
molecular  unions,  and  are  not  only  found 
in  living  structures,  they  are  to  be  met  in 
inorganic  colloids. 

It  has  been  seen  above  that  with  the 
exception  of  carbon,  and  in  a  lesser  degree 
silicon,  the  other  elements  do  not  possess  in 
any  marked  degree  the  power  of  self-union, 
and  so  do  not  form  enormous  single  molecules 
such  as  fats,  carbohydrates,  and  proteins, 
but  many  of  them  do  possess  the  power  of 
molecular  union  to  form  colloids  with  as 
many  as  sixty  molecules  united  without 
any  atomic  unions  to  form  colloids. 

The  compounds  of  carbon  possess  both  these 
properties  for  increasing  structural  complexity 
viz.,  large  molecules  and  power  of  colloidal 
union,  and  hence  these  form  the  best  material 


EVOLUTION   OF   COLLOIDS      123 

in    nature    for    the    construction    of    living 
organisms. 

Before  passing  on  to  the  energetics  of 
living  matter,  some  consideration  must  be 
accorded  to  the  problems  of  molecular  com- 
bination and  the  formation  of  colloids,  for 
all  living  structures  consist  of  colloids.  Such 
colloids  are  either  active  in  solution  in  water, 
or  are  dead  inactive  masses  formed  by  the 
dissolved  living  colloids  and  thrown  out  as 
supporting  meshworks,  mechanisms  for  sup- 
port, and  membranes  surrounding  and  dividing 
off  the  living  units  or  cells  from  one  another. 
Thus,  both  in  that  grosser  mechanical  structure 
visible  under  the  microscope  which  holds  the 
organic  unit,  or  cell,  together,  and  in  its 
ultra-microscopic  intrinsically  living  and  active 
part,  the  living  organism  is  made  up  of 
colloidal  matter. 


CHAPTER   VI 

EVOLUTION   OF   COLLOIDS 

This  chapter  in  the  history  of  evolution  is 
one  that  has  suffered,  until  quite  recently, 
from  a  strange  neglect,  at  the  hands  of  both 


124    ORIGIN  AND  NATURE  OF  LIFE 

chemists  and  biologists,  although  it  happens 
to  be  that  one  which  lies  at  the  very  threshold 
of  life.  It  was  opened  just  fifty  years  ago 
by  Thomas  Graham,  who  introduced  the 
word  colloid  because  one  of  the  most  typical 
members  is  gelatine  (L.  colla,  glue).  This 
earliest  pioneer  with  a  wonderful  clearness 
of  vision  recognized  the  close  relationship  of 
colloids  to  the  phenomena  of  life,  and  with 
such  a  lead  it  is  remarkable  that  the  study 
was  left  languishing  for  nearly  forty  years. 
In  the  last  decade  it  has  become  a  centre  of 
feverish  industry  with  ever-expanding  rela- 
tionships both  to  modern  industries,  and  to 
the  scientific  problems  of  bio-chemistry  and 
medicine. 

One  reason  for  this  neglect  undoubtedly 
lay  in  the  fixed  attitude  of  the  chemical 
theory  of  the  time  towards  the  subject  of 
atomic  valencies.  It  was  deemed  inconceiv- 
able that  a  fully  saturated  chemical  substance, 
in  the  atomic  sense,  could  enter  afresh  into 
a  new  round  of  chemical  activities,  in  which 
atoms  as  such  did  not  play  a  part,  but  where 
the  whole  molecule  behaved  as  an  atom. 
In  fact,  to  the  majority  of  chemists,  this  is 
still  a  heterodox  opinion,  and  they  prefer 
to  ascribe  such  molecular  actions  to  something 
which  they  describe  as  "  residual  affinity. " 


EVOLUTION   OF   COLLOIDS      125 

Legions  of  cases  exist  in  which  two  or  more 
molecules,  themselves  completely  saturated 
atomically,  and  incapable  of  attaching  to 
their  molecule  a  single  additional  atom, 
unite  most  strongly  to  one  another  with 
evolution  of  energy,  and  this  without  the 
loosening  of  any  atomic  affinities.1 

The  theory  of  atomic  valencies  entirely 
fails  to  account  for  such  combinations, 
and  so  through  lack  of  invention  and  scientific 
imagination,  they  were  simply  cast  upon  one 
side  and  ignored  by  the  chemist  as  purely 
physical  phenomena,  just  as  if  that  removed 
them  from  the  pale  of  research  by  throwing 
them  into  the  dust-heap  of  another  scientist. 
The  physicist  was  content  to  classify  them  with 
a  confused  heap  of  phenomena  ascribed  to 
surface  reactions,  or  condensations  upon 
surfaces,  and  having  invented  the  term 
adsorption  to  designate  such  phenomena, 
the  physicist,  too,  rested  upon  his  laurels. 

Now,  in  many  cases,  the  amount  of  energy 
set  free  as  heat,  when  a  number  of  molecules, 
each  completely  saturated  atomically,  unite 
together  is  of  far  too  high  an  order  of  magni- 

1  For  details,  the  reader  acquainted  with  chemistry 
is  referred  to  a  paper  entitled  "  The  role  played  by  mole- 
cular affinities  in  bio-chemical  reactions,"  Benjamin  Moore, 
Archivio  di  Fisiologia,  vol.  vii,,  1909,  Anniversary 
volume  in  honour  of  Guilio  Fano. 


126    ORIGIN  AND  NATURE  OF  LIFE 

tude  to  ascribe  the  result  to  a  residual 
atomic  affinity,  which  is  absolutely  powerless 
to  add  another  single  atom  to  the  molecule, 
but  can  nevertheless  set  so  large  a  store 
of  energy  free  by  uniting  with  another 
saturated  molecule  without  any  atomic  dis- 
placements. 

The  experimental  evidence  is  complete  and 
convincing  that  these  saturated  molecules 
possess  no  remaining  trace  of  atomic  affinity, 
and  that  the  molecular  unions  must  arise 
not  from  atomic  affinities,  but  from  "  mole- 
cular affinities." 

Moreover,  in  such  molecular  combinations 
between  molecules  behaving  as  units,  there 
are  found  properties  which  exactly  reproduce 
on  the  molecular  scale,  the  analogues  of  the 
"  atomic  affinities  "  and  "  atomic  valencies  " 
described  in  the  previous  chapter,  and  these 
it  is  proposed  may  be  called  "  molecular 
affinity  "  and  "  molecular  valency." 

Such  molecular  affinity  and  valency  do  not 
belong  to  any  particular  atom  or  group 
in  the  molecule,  but  are  a  property  of  the 
molecule  as  a  whole. 

Molecular  affinity  is  a  specific  property  just 
as  is  atomic  affinity.  Some  pairs  of  molecules 
will  not  unite,  under  ordinary  circumstances, 
to  form  molecular  unions,  so  feeble  is  their 


EVOLUTION    OF    COLLOIDS      127 

mutual  molecular  affinity ;  others  unite 
violently  with  great  evolution  of  heat. 

As  to  molecular  valency  some  pairs,  or  sets, 
of  molecules  will  unite  one  to  one,  others 
two  to  one,  and  so  on.  Also,  the  relative 
numbers  so  uniting  are  fixed  by  the  chemical 
nature  of  the  reacting  molecules,  and,  curiously 
enough,  sometimes  there  are  two  ratios  of 
union,  just  as  it  has  been  seen  in  the  previous 
chapter  that  the  same  element  may  have 
two  valencies,  the  lower  one  arising  as  a  result 
of  partial  self-saturation. 

The  numerical  values  of  molecular  valencies 
often  reach  far  higher  figures  than  those 
of  atomic  valencies.  It  was  pointed  out  that 
atomic  valencies  probably  did  not  exceed  a 
doubtful  hexi-valency  in  a  few  elements. 
But  an  undoubted  molecular  valency  in  one 
saturated  substance  of  twenty-four  fold  that 
of  the  other  substance  united  with  it,  is  seen 
in  at  least  one  group  of  molecular  unions. 

Doubt  has  been  cast  upon  the  chemical 
nature  of  these  molecular  unions,  because  it 
is  difficult  in  many  cases  to  prove  that  there 
is  always  a  definite  ratio  in  the  numbers  of 
the  molecules  aggregating  together. 

In  all  such  cases  it  must  be  remembered 
that  it  is  difficult  to  obtain  the  point  where 
interaction  between  the  substances  is  com- 


128    ORIGIN  AND  NATURE  OF  LIFE 

plete,  and  to  remove  the  completed  product 
from  intermixture  with  incomplete  stages, 
and  from  the  two  or  more  unchanged  reacting 
substances.  For  these  complex  molecular 
unions  give  rise  to  matter  in  a  new  form  which 
cannot  be  so  easily  dealt  with.  In  many- 
cases,  when  saturation  is  complete  there  are 
found  to  be  exact  molecular  relationships, 
just  as  definite  as  those  found  in  simple 
inorganic  mono-molecules. 

But  the  admission,  even,  of  varying  mole- 
cular relationships  in  the  multi-molecule, 
does  not  preclude  the  reaction  from  being 
truly  chemical.  A  new  territory  is  here 
being  investigated,  and  it  would  not  be  true 
philosophy  to  expect  details  to  remain  the 
same  in  this  region  as  in  the  mono-molecular 
one.  When  molecules  begin  to  interplay, 
instead  of  atoms,  some  modifications  are 
naturally  to  be  expected.  Also  the  exact 
atomic  relationships  in  the  composition  of  a 
mono-molecule,  on  account  of  the  low  relative 
valencies  of  the  atoms,  can  be  followed  with 
great  experimental  exactitude.  But,  when 
instead  of  atomic  valencies  rising  no  higher 
than  four  or  five,  there  are  substituted 
molecular  valencies  of  thirty  to  sixty,  then 
the  problem  of  following  out  exact  relative 
numbers  of  molecules  of  each  constituent  in 


EVOLUTION    OF    COLLOIDS      129 

the  multi-molecule,  becomes  experimentally 
almost  impossible.  It  is  easy  to  discover 
by  analysis  whether  a  mono-molecule  contains 
three  or  four  atoms  of  a  given  element,  but 
the  query  as  to  whether  a  given  multi-molecule 
contains  sixty  or  sixty-one  molecules  of  a 
given  substance  is  obviously  more  difficult 
of  solution.  The  same  difficulty  is  found 
in  the  region  of  the  mono-molecule,  such  as 
those  dealt  with  in  the  last  chapter.  When 
there  are  over  twenty  atoms  of  hydrogen 
in  the  molecule  of  a  fatty  acid,  the  chemist 
is  often  unable  to  determine  from  the  results 
of  an  analysis,  whether  the  figure  assigned 
in  the  formula  should  be,  say,  twenty  or 
twenty-one.  Finally,  it  is  to  be  remembered 
that  even  in  inorganic  chemistry,  compounds 
are  to  be  found  in  a  similarly  constituted 
series  with  varying  numbers  of  atoms,  and 
accordingly  the  occurrence  of  a  series  of 
molecular  combinations  between  two  saturated 
molecules  with  varying  relative  numbers  of 
molecules  is  no  good  evidence  against  the 
chemical  nature  of  molecular  combination. 
All  molecular  combinations  do  not  lead  to 
the  formation  of  colloids  :  indeed,  molecular 
combination  in  the  case  of  the  greater  half 
of  the  inorganic  substances  known  as  crystal- 
loids (as  distinguished  from  colloids)  forms 


130    ORIGIN  AND  NATURE  OF  LIFE 

the  initial  step  in  crystal  formation.  The 
distinguishing  feature  of  the  colloid  is  that 
the  molecular  unions  shall  be  of  a  feeble 
unstable  kind  with  very  little  evolution  of 
energy.  This  condition  has  been  termed  the 
meta-stable  condition,  and  is  seen  at  its 
acme  in  living  colloids.  The  true  inorganic 
colloids  showing  typically  those  characteristic 
properties  which  distinguish  the  colloidal 
class  from  the  crystalloidal  class  of  bodies 
are  also  formed  without  much  evolution  of 
energy.  Between  the  two  classes  lie  all 
kinds  of  intermediate  grades,  and  it  is  only 
by  contrasting  a  typical  colloid  with  a  typical 
crystalloid  that  those  characteristic  features 
have  become  obvious  which  will  presently  be 
described. 

Crystallization  of  a  substance  from  solution 
in  well-formed  crystals  of  definite  form  is 
usually  regarded  as  one  of  the  best  criteria 
of  definite  chemical  constitution  and  purity. 
As  a  rule,  to  which  there  are  some  notable 
exceptions,  colloids  do  not  form  saturated 
solutions  like  crystalloids,  and  then  crystallize 
out  giving  an  increasing  crop  of  crystals 
as  the  solvent  evaporates  off.  After  crystals 
once  begin  to  form  in  a  solution  of  a  crystal- 
loid, the  mother  liquor  over  the  crystals 
remains  of  a  constant  concentration,  and  this 


EVOLUTION    OF    COLLOIDS      131 

is  preserved  by  the  crystals  growing  larger 
and  increasing  in  number.  In  a  solution  of 
a  colloid  as  a  rule  no  saturation  point  is 
reached,  the  solution  becomes  thicker  and 
thicker,  and  finally  forms  a  viscid  gum 
especially  at  lower  temperatures,  and  the 
gum  holds  tenaciously  to  the  last  portions 
of  the  solvent.  As  typical  examples  there 
may  be  mentioned  aqueous  solutions  of  com- 
mon salt  (a  crystalloid)  and  of  ordinary  gum 
arabic  (a  colloid).  Having  defined  this  pro- 
perty of  crystallization  as  something  properly 
typical  of  crystalloids,  which  caused  Graham 
to  give  them  their  name  which  distinguishes 
them  from  colloids,  let  us  now  briefly  take 
up  the  subject  of  molecular  combinations, 
molecular  affinities  and  molecular  valencies, 
before  passing  on  to  the  consideration  of  the 
other  main  properties  of  the  colloids. 

As  a  typical  example  of  molecular  com- 
pounds amongst  crystalloids,  there  may  be 
taken  three  crystalline  substances,  closely 
related  chemically,  viz.,  sodium  chloride 
(common  salt),  sodium  bromide,  and  sodium 
iodide.  When  their  respective  solutions  in 
water  concentrate,  each  substance,  at  a 
definite  concentration  in  each  case,  separates 
out  in  crystalline  form  from  the  water. 
Now  each  of  these  salts  is  completely  saturated 


132    ORIGIN  AND  NATURE  OF  LIFE 

atomically,  the  molecule  consisting  of  only 
two  atoms  in  each  case,  and  these  atoms 
monads.  In  each  case  there  is  in  the  molecule 
one  atom  of  sodium  united  respectively  to 
one  of  chlorine,  one  of  bromine,  and  one 
of  iodine.  A  clearer  case  of  atomic  saturation 
could  not  be  found  ;  there  is  no  known  way 
by  which  an  atom  of  any  kind  can  be  intro- 
duced without  splitting  up  the  molecule.  When 
the  three  crystalline  salts  separate  out  from 
their  three  respective  saturated  solutions, 
it  is  found,  however,  that  while  the  sodium 
chloride  molecules  have  formed  themselves 
into  crystals  consisting  entirely  of  sodium 
chloride,  the  sodium  bromide  and  the  sodium 
iodide  have  separated  in  crystals  containing 
water.  Analysis  of  these  latter  two  kinds 
of  crystals,  moreover,  demonstrates  that  the 
bromide  and  iodide  and  their  respective 
amounts  of  water  are  so  beautifully  pro- 
portioned that  there  are  in  each  case  exactly 
two  molecules  of  water  to  each  molecule  of 
salt.  This  does  not  mean  that  there  is  the 
same  percentage  of  water  in  the  sodium 
bromide  as  in  the  sodium  iodide  crystals, 
for  the  sodium  iodide  molecule  is  much 
heavier  than  the  sodium  bromide  molecule. 
But  when  the  percentages  are  worked  out  on 
the  basis  of  molecular  weights,   then  it  is 


EVOLUTION    OF    COLLOIDS      133 

discovered  that  the  molecules  have  united 
exactly  in  the  ratio  of  two  molecules  of  water 
to  one  molecule  of  bromide  or  iodide,  respec- 
tively. 

But  this  is  precisely  the  proof  upon  which 
the  whole  atomic  theory  rests,  by  means  of 
which  Dalton  proved  that  in  atomic  reactions, 
union  occurred  always  proportionately  to 
atomic  weights,  or  their  multiples.  If  the 
argument  holds  for  atoms,  it  is  difficult 
to  see  why  it  is  to  be  refused  for  molecules. 

In  this  reaction  both  salt  and  water  are 
completely  saturated  compounds,  and  they 
unite  without  any  atoms  being  displaced  or 
set  free.  Specific  molecular  affinity  is  shown 
by  its  absence  in  the  case  of  the  sodium 
chloride,  and  its  presence  in  the  other  two 
cases.  Molecular  valency  is  also  illustrated 
by  the  exact  relationship  of  two  molecules  to 
one.  The  two  salts  possess  an  equal  molecular 
valency  which  is  double  that  of  the  water 
molecule. 

The  facts  as  to  true  chemical  union  are  also 
demonstrated  by  the  large  amount  of  heat 
set  free  when  the  molecular  union  between  the 
salts  and  water  takes  place. 

The  quantitative  difference  in  the  amount 
of  molecular  chemical  affinity  is  easily  shown 
by  measuring  the  amounts  of  heat  evolved  in 


134   ORIGIN  AND  NATURE  OF  LIFE 

the  two  cases.  If  the  crystalline  salts  are 
heated  above  the  temperature  of  boiling 
water,  the  water  of  the  crystals  (water  of 
crystallization)  is  driven  off,  and  the  dry  or 
anhydrous  salts  are  obtained.  When  these 
salts  are  allowed  to  cool  and  then  mixed 
with  just  enough  water  to  form  once  more 
the  crystals,  the  mixture  as  it  crystallizes 
grows  quite  warm. 

When  the  chemist  measures  such  quantities 
of  heat,  he  uses  a  quantity  of  the  salt  equal 
to  the  molecular  weight  of  the  salt  in  grammes 
(the  unit  of  weight  of  the  decimal  system), 
and  he  expresses  the  heat  developed  in  units, 
which  he  terms  calories.  The  calory  is  the 
amount  of  heat  required  to  heat  100  grammes 
of  water  by  one  degree  Centigrade,  and  is 
written  down  as  K  in  the  chemist's  shorthand. 
Now  when  an  amount  of  dried  sodium  bromide 
expressing  the  molecular  weight  in  grammes 
(i.e.,  about  110  grammes),  is  allowed  to  unite 
with  twice  the  molecular  weight  of  water  in 
grammes  (i.e.,  36  grammes),  the  amount  of 
heat  developed  is  found  to  be  45  K,  or  an 
amount  of  heat  approximately  sufficient  to 
heat  45  grammes  of  water  from  freezing  point 
to  boiling  point. 

The  figure  for  the  iodide  is  higher  still, 
standing  at  53  K. 


EVOLUTION   OF   COLLOIDS      135 

Here,  then,  is  conclusive  proof  as  to  these 
molecular  affinities  and  valencies.  The  chlor- 
ide has  no  measurable  affinity,  and  separates 
without  water,  the  bromide  and  iodide  have 
specific  and  different  affinities,  and  a  molecular 
valency  double  that  of  the  water  molecule. 

This  is  not  an  isolated  case ;  the  majority 
of  inorganic  crystalline  substances  show  the 
same  effect,  and  exhibit  specific  variations  in 
molecular  affinity  and  molecular  valency. 
Here  are  a  few  examples  from  the  wealth  of 
them  in  the  literature : — Calcium  nitrate, 
four  molecules  of  water,  112  K  ;  manganous 
sulphate,  five  molecules,  138  K  ;  nickel  chlor- 
ide, six  molecules,  203  K  ;  magnesium  sul- 
phate, seven  molecules,  241 K ;  barium 
hydrate,  eight  molecules,  254  K ;  sodium 
carbonate,  ten  molecules,  217  K ;  alkaline 
sodium  phosphate,  twelve  molecules,  284  K. 

These  examples  prove  both  varying  molecu- 
lar valency  from,  substance  to  substance,  and 
also  varying  molecular  affinity,  and  the  basis 
of  proof  is  exactly  that  admitted  for  the 
atomic  analogues. 

Common  experience  proves  the  same  thing, 
when  almost  any  crystalline  body  is  dissolved 
in  water,  the  solution  is  cooled  thereby. 
The  cause  of  the  cooling  is  that  the  dissolved 
substance  produces  a  pressure  in  the  solution 


136    ORIGIN  AND  NATURE  OF  LIFE 

just  as  if  it  had  been  compressed  into  a  steel 
gas  cylinder,  the  pressure  so  developed 
within  the  solution  being  called  osmotic 
pressure.  This  pressure  means  work  done, 
and  the  energy  must  be  got  from  some  other 
form.  It  is  obtained  by  the  cooling  of  the 
solution.  If  now,  instead  of  the  crystallized 
substance,  an  equal  amount  of  the  dried  salt 
be  used,  then  the  temperature,  in  practically 
every  case,  rises  instead  of  falling,  showing 
that  the  energy  set  free  by  the  molecular 
affinity  of  the  anhydrous  salt  and  water, 
is  greater  than  the  energy  needed  for  the 
development  of  the  osmotic  pressure  energy. 
In  fact,  the  figures  given  above,  in  each  case 
only  express  the  difference  between  these  two 
amounts  of  energy,  and  the  true  molecular 
affinity  is  measured  by  an  amount  greater 
than  them,  at  present  unknown  to  us. 

By  what  scheme  can  this  molecular  affinity 
and  valency  be  visualized  ?  The  human 
mind  always  searches  for  some  outward 
and  visible  sign  of  a  scientific  faith,  so  here 
is  a  simile. 

Suppose  the  electrons  and  atoms  and 
molecules  could  be  magnified  by  a  powerful 
microscope  that  would  make  the  electrons 
visible  to  the  eye,  then  it  may  be  supposed 
that  a  system  might  be  revealed  such  as  the 


EVOLUTION    OF    COLLOIDS      137 

telescope  displays  to  the  astronomer.  A  solar 
system  might  be  seen  representing  the  mole- 
cule, the  sun  and  its  attendant  primary  planets 
would  indicate  the  atoms,  and  the  satellites 
of  the  planets  would  stand  for  the  electrons. 
Closer  examination  under  this  imaginary 
microscope  might  reveal  that  the  sun  and  the 
attendant  planets,  and  their  satellites,  were, 
as  a  whole,  revolving  in  concert  with  other 
suns  and  other  solar  systems,  and  this  latter 
motion  would  represent  molecular  affinity. 
The  variations  in  numbers  in  the  various 
systems  in  equipoise  would  stand  for  chemical 
valency  at  each  stage.  Some  planets  would 
have  only  one  moon,  others  four,  in  a  solar 
system  the  number  of  planets  might  vary, 
and  in  the  constellations  there  might  be 
similar  balances  amongst  the  constituent 
solar  systems. 

It  is,  perchance,  but  an  analogy,  but  it  is 
one  which  fittingly  illustrates  the  facts  of  the 
case. 

Water  is  not  the  only  substance  which  forms 
these  molecular  unions  with  crystalloids, 
alcohol  and  other  organic  substances  may 
replace  water  of  crystallization,  or,  apart 
from  water,  different  crystalloids  which  come 
out  of  solution  in  the  same  crystalline  form 
can  replace  each  other  in  the  same  crystal. 


138    ORIGIN  AND  NATURE  OF  LIFE 

An  example  of  interest  to  the  biological 
chemist,  is  the  molecular  union  of  one  molecule 
each  of  common  salt  and  grape  sugar,  which 
separates  in  crystalline  form  from  a  common 
solution  of  these  two  substances,  and  this  is 
but  one  instance  amongst  many  occurring 
in  the  body,  too  specialized  to  give  in  detail 
in  a  general  volume. 

With  this  outline  sketch  we  may  leave  the 
question  of  molecular  unions  amongst  crystal- 
loids, and  pass  on  to  the  remaining  properties 
of  colloids. 

All  the  known  properties  of  colloids  can  be 
traced  to  feeble  molecular  affinities  between 
the  molecules  themselves,  causing  them  to 
unite  into  multi-molecules  or  "  solution  aggre- 
gates," and  to  a  balance  between  such  affini- 
ties and  similar  feeble  affinities  for  crystalloids 
in  common  solution  with  them,  and  for  the 
molecules  of  the  solvent.  The  whole  essence 
of  the  colloidal  condition  is  that  of  a  balance 
of  play  of  energies  in  the  most  delicate 
equilibrium.  Quantitative  differences  exist, 
giving  classes  of  colloids  which  differ  from  one 
another  in  stability.  Some  are  upset  with 
the  greatest  ease  by  either  adding  a  slight  ex- 
cess of  crystalloid  to  the  solution,  or  by 
heating  the  solution  a  few  degrees  in  tempera- 
ture, others  more  delicate  still  even  undergo 


EVOLUTION   OF   COLLOIDS      139 

slow  spontaneous  change  when  left  to  them- 
selves. On  the  other  hand,  colloids  are 
known  of  great  stability  which  are  not  easily 
upset  even  by  boiling  their  solutions,  or  by 
saturating  them  with  salt. 

These  variations  are  a  peculiarity  of  the 
colloidal  state  of  great  importance  in  relation- 
ship to  the  phenomena  of  life. 

A  great  many*  colloids  show  two  distinct 
forms  of  arrangement  of  their  multi-molecules, 
known  respectively  as  hydrosols  and  hydrogels. 
Thus  a  solution  of  glue  or  gelatine  at  such  a 
temperature  that  it  is  fluid  and  mobile  is  a 
hydrosol ;  at  a  lower  temperature  it  sets  into 
a  solid  jelly,  and  is  then  a  hydrogel.  The 
clear  fluid  part  of  the  blood,  known  as  plasma, 
or  the  clear  uncooked  fluid  of  the  white  of  an 
egg  contains  its  nutrient  protein  substances 
in  the  form  of  hydrosols.  When  either  fluid 
is  heated  nearly  to  the  boiling  point  of  water 
it  sets  into  a  solid  jelly  and  then  forms  a 
hydrogel.  The  effect  of  temperature  it  will 
be  noticed,  is  in  the  opposite  direction : 
in  the  gelatine,  which  becomes  fluid  at  the 
higher  temperature,  while  the  egg-white  and 
blood-plasma  set  solid  or  coagulate  at  the 
higher  temperature.  There  is  also  this  import- 
ant difference  that  the  process  is  reversible 
in  the  case  of  the  gelatine,  which  is  hence 


140   ORIGIN  AND  NATURE  OF  LIFE 

called  a  reversible  colloid ;  while  in  the 
other  two  cases  the  hydrogel  (or  coagulum, 
as  it  is  also  called),  is  permanent,  and  a 
hydrosol  is  not  again  formed  as  the  tempera- 
ture falls. 

In  the  condition  of  the  hydrosol,  the 
multi-molecules,  or  solution  aggregates,  are 
each  free  and  microscopically  invisible,  and 
so  far  as  the  properties  of  solution  are  con- 
cerned, each  behaves  as  would  a  single  unit, 
or  molecule  in  solution.  When  gel  formation 
occurs,  the  multi-molecules  aggregate  together 
and  form  a  system  made  up  of  two  distinct 
kinds.  It  is  called  a  diphasic  system,  and  is 
no  longer  a  true  solution.  It  is  in  this  way 
that  there  arise  foam  structures,  and  the 
protoplasmic  networks  and  structures  seen 
in  living  cells,  and  also  as  artifacts,  or  products 
of  death  and  fixation  by  chemicals,  in  dead 
cells.  When  the  colloidal  solution,  as  a  result 
of  changes  in  environment,  forms  two  phases, 
it  does  so  by  separating  into  two  systems,  in 
one  of  which  there  is  still  a  true  solution, 
but  a  comparatively  dilute  one,  of  the  smaller 
multi-molecules,  and,  in  the  other,  relatively 
huge  molecular  complexes  have  separated 
with  comparatively  little  of  the  solvent. 
In  the  limit,  the  fluid  part  may  be  pure 
solvent  and  the  particulate  part  pure  colloidal 


EVOLUTION   OF   COLLOIDS      141 

matter  without  solvent.  This  di-phasic 
separation  is  very  interesting  because  it 
illustrates  so  many  of  the  origins  of  the 
structures  shown  by  the  microscope  in  cells, 
and  in  colloidal  solutions  and  suspensions 
in  general.  If  the  greater  part  consists  of 
the  fluid  phase  when  separation  occurs,  then 
the  particulate  part  may  either  gather  into 
little  spherules  so  widely  apart  that  they 
do  not  touch,  then  an  emulsion  is  the  result ; 
or  there  may  be  just  such  proportions,  that 
the  concentrated  phase  forms  a  meshwork 
between  small  spheres  of  the  dilute  phase. 
In  this  way  a  foam  or  a  reticulum  may  be 
formed,  and  the  meshwork  according  to 
circumstances  of  physical  and  chemical  en- 
vironment may  take  many  forms.  Again,  the 
more  concentrated  phase  may  predominate, 
surrounded  by  a  lacunar  setting  of  fluid, 
when  a  granular  network  results,  coarsely  or 
finely  granular,  according  to  the  degree  of 
size  of  the  aggregate  of  semi-solid  material. 
These  varieties  may  all  be  recognized 
by  the  histologist,  when  examining  the 
microscopical  appearances  of  cells.  From 
such  causes,  differences  in  staining  with 
histological  reagents  and  in  the  appearances 
with  polarized  or  reflected  light  arise,  and 
these  are  indispensable  aids  in  differentiating 


142    ORIGIN  AND  NATURE  OF  LIFE 

and  diagnosing  various  kinds  of  cells,  and  in 
recognizing  under  the  microscope  the  micro- 
organisms which  produce  disease. 

A  division  of  colloids  has  been  mentioned 
above  into  reversible  and  irreversible,  but  it 
is  probable  that  even  irreversible  colloids, 
if  treated  delicately  enough,  can  be  reversed 
if  the  process  is  not  carried  too  far.  This  has 
been  shown  by  the  aid  of  the  ultra-microscope, 
using  one  of  the  protein  bodies  of  the  blood 
plasma.  If  a  solution  of  this  colloid  placed 
in  the  field  of  the  ultra-microscope,  be 
cautiously  warmed  to  just  below  the  point 
of  temperature  which  would  cause  it  to 
coagulate  irreversibly,  then  it  is  observed 
that  the  view  which  was  previously  clear 
becomes  suddenly  filled  with  an  innumerable 
host  of  moving  particles  which  rapidly 
increase  and  become  more  prominent.  If 
at  this  stage  the  heating  process  be  stopped 
and  the  solution  allowed  to  cool  slowly,  as 
the  temperature  falls  all  these  particles 
dissolve  and  disappear,  and  this  appearance 
and  disappearance  can  be  many  times  repeated. 
If  the  heating  be  carried  so  far,  however, 
that  particles  visible  microscopically  even  to  a 
high  power  of  the  ordinary  microscope  are 
formed,  then  the  process  ceases  to  be 
reversible. 


EVOLUTION    OF    COLLOIDS      143 

This  observation  is  one  of  high  import  in 
relationship  to  rhythmic  processes,  which 
occur  in  many  forms  of  living  cells,  such  as 
the  nerve  cells  that  guide  respiration,  and  the 
cells  of  contractile  tissues  like  those  of  the 
beating  heart. 

The  view  was  foreshadowed  long  ago  by 
Sidney  Ringer  that  muscular  contraction  is  an 
incipient  coagulation  which  becomes  reversed 
and  again  repeated  in  cyclic  alternation. 
This  view  was  suggested  by  similarities  in 
chemical  character  between  the  products  of 
muscular  contraction,  and  that  coagulation 
of  the  muscle  juices  which  causes  muscular 
stiffening  or  rigor  mortis  after  death.  Heat 
is  not  the  only  cause  which  can  induce 
incipient  coagulation ;  a  slight  change  in 
chemical  reaction  from  alkaline  towards  acid 
causes  opalescence  due  to  a  running  together 
of  the  colloid  into  larger  aggregates,  which 
commence  to  be  big  enough  to  interfere  with 
the  light  waves,  and  so  cause  opalescence. 
If  the  amount  of  acid  be  increased  the  opales- 
cence passes  into  true  coagulation.  Now  a 
living  cell,  such  as  a  nerve-cell,  may  furnish 
rhythmical  stimulation  to  another,  or  itself 
show  rhythmical  contractions,  as  in  the  case 
of  a  muscle- cell,  because  it  heaps  up  between 
each  contraction  as  a  result  of  the  chemical 


144    ORIGIN  AND  NATURE  OF  LIFE 

changes  going  on  within  it,  such  feeble  acids 
as  carbonic  or  lactic  acid.  This  leads  to 
molecular  aggregation  of  the  colloids  of  the 
cell,  and  this  culminates  in  a  stimulus  or 
contraction  in  which  the  acid  is  discharged, 
and  the  whole  system  reverses  or  reverts  to 
its  original  condition. 

It  is  thus  seen  that  in  the  typical  colloidal 
solution  there  exists  a  most  delicate  balance 
of  the  feeble  affinities  of  the  colloidal  molecules, 
so  that  within  narrow  limits  they  can  build 
together  or  be  pulled  apart,  and  the  value  of 
this  in  life  processes  is  obvious. 

Next  there  must  be  considered  the  balancing 
of  these  affinities  against  similar  affinities 
for  the  solvent  and  for  the  crystalloids  of 
inorganic  or  organic  nature  present  in  true 
solution  along  with  the  colloids. 

The  affinity  between  colloid  and  solvent  is 
shown  by  the  failure  to  form  saturated  solu- 
tions and  separate  out  as  crystalloids  do ;  it  is 
also  shown  by  the  tendency  of  the  colloidal 
multi-molecules  to  accumulate  upon  any 
interface  and  alter  conditions  there.  Such 
accumulations  are  accompanied  by  change  in 
what  is  called  surface-tension  (or  the  energy 
distribution  at  the  interface  between  two 
layers).  It  is  as  a  result  of  this  that  colloidal 
solutions  readily  form  froths,  even  in  most 


EVOLUTION    OF    COLLOIDS      145 

dilute  solutions,  for  all  the  colloid  tends  to 
accumulate  at  the  interface.  The  frothing  of 
soap  solutions,  and  of  all  albuminous  solutions, 
with  formation  of  a  lather  of  bubbles  is  an 
example  of  this,  and  what  happens  between 
air  and  a  colloidal  solution  can  also  happen 
between  such  a  solution  and  solid  or  fluid 
particles  suspended  in  it.  Such  an  effect  is 
seen  in  the  suspension  of  fat  in  milk  or  cream. 
Colloids  such  as  gum  arabic  are  similarly 
used  by  the  pharmacist  to  hold  solid  drugs 
in  suspension. 

When  the  colloidal  particles  have  once 
been  attracted  into  the  surface  layer  they 
form  a  highly  concentrated  solution  or  fluid 
film  there,  and  such  concentration  leads  to 
formation  of  solid  films  as  well  as  to  the 
synthesis  and  building  up  of  more  complex 
substances  in  living  cells. 

High  concentration  in  the  surface  layer 
acts  much  as  increasing  pressure  does  in 
causing  gases  to  liquefy  or  condense,  and 
favours  chemical  union. 

An  example  of  such  action  is  seen  in  the 
skin  which  forms,  and  again  re-forms  as  often 
as  it  is  skimmed  off,  on  the  surface  of  a  glass 
of  warmed  milk  while  cooling,  or  on  a  cup  of 
cocoa  and  milk.  Familiar  as  this  observation 
is,  it  furnishes  an  example  of  the  manner  in 


146    ORIGIN  AND  NATURE  OF  LIFE 

which  unicellular  organisms  often  form  their 
external  envelopes,  and  of  the  manner  in 
which  cells  provide  themselves  with  limiting 
membranes  or  cell-walls. 

The  chief  colloid  of  the  milk,  on  account 
of  its  affinities,  accumulates  on  the  surface, 
the  accumulation  gives  increased  concentra- 
tion, the  pressure  of  the  increased  concen- 
tration causes  the  multi-molecules  to  build 
together,  the  larger  molecules  fall  out  of 
solution  as  particles,  and  these  join  to  form 
a  close  network  or  film. 

Nor  is  it  only  film  formation  and  delimita- 
tion of  the  constituent  cells  of  an  organism 
from  one  another  that  is  served  by  this 
property  of  colloids  of  concentrating  at  an 
interface.  Such  interfaces  occur  on  the 
surfaces  of  the  minute  microscopic  granules 
which  are  found  in  all  living  cells.  Here 
also  there  concentrate  not  only  ordinary 
colloids  present  in  solution  within  the  cell, 
but  bodies  formed  by  the  cell  called  ferments 
or  enzymes,  themselves  also  colloids. 

This  concentration  within  the  cell  on  sur- 
faces favours  union,  and  it  is  in  this  way,  by 
continued  aggregation,  that  starch  granules, 
protein  granules,  and  drops  of  fat  or  oil, 
grow  within  living  cells. 

It  is  a  wonderful  adaptation  of  nature  that 


EVOLUTION   OF   COLLOIDS      147 

these  ferments  which  produce  union  and 
reduplication  within  the  living  cells,  are 
exactly  the  same  substances  which  digest  and 
break  up  the  food  when  they  are  thrown  out 
by  the  digestive  glands  into  the  alimentary 
canal,  and  so  form  soluble  matter  capable  of 
absorption. 

The  food  must  be  broken  down  into  chemical 
building  stones  from  which  the  animal  can 
rebuild  its  own  special  and  very  specific 
colloidal  structures,  which  vary  from  one 
species  of  animal  to  another.  This  chemical 
detachment  is  achieved  by  means  of  soluble 
ferments,  or  enzymes,  discharged  by  the  cells 
of  the  digestive  glands.  In  dilute  solution 
these  attack  the  starches,  fats,  and  proteins, 
reversing  the  building  up  processes  described 
in  the  previous  chapter.  The  smaller  mole- 
cules so  formed  are  taken  up  into  the  body 
and  reach  the  cells.  They  undergo  local 
concentration  in  the  cells,  and  these  being 
brought  again  in  contact  with  exactly  the  same 
ferments,  also  locally  concentrated  on  surfaces, 
exactly  the  opposite  effect  occurs,  and  the 
building  back  into  multi-molecules  com- 
mences. In  dilute  solution  there  is  breaking 
up,  in  concentrated  solution  there  is  con- 
densation and  re-duplication.  It  is  only 
when  chemical  unions  are  feeble  and  small 


148    ORIGIN  AND  NATURE  OF  LIFE 

amounts  of  energy  are  absorbed  or  set  free 
that  chemical  energy  and  pressure  energy  (or 
energy  of  concentration)  can  balance  in  this 
remarkable  way. 

The  balance  so  established  enables  the 
living  cell  to  deal  with  its  nutrition  and 
preserve  a  nearly  constant  amount  of  soluble 
pabulum  within  its  contents.  Suppose  the 
living  cell  is  supplied  with  more  nutrition 
than  it  requires  at  the  moment  for  immediate 
oxidation  to  yield  energy  for  its  life-processes, 
then  the  increased  pressure  of  the  soluble 
part  causes  condensation  on  the  multi- 
molecules  of  colloid.  This  concentration, 
aided  by  the  ferments,  causes  reduplication, 
and  building-up  of  fats,  starches,  and  proteins 
into  more  multi-molecules,  and  finally  granules 
are  formed. 

Now,  suppose  supplies  of  nutrition  decrease 
or  fail,  then  the  cell  uses  up  its  soluble  material, 
so  obtaining  energy  which  it  converts  into 
various  forms  of  activity.  As  a  result,  the 
pressure  of  soluble  matter  decreases,  now  the 
enzymes  commence  to  act  upon  the  multi- 
molecules  and  break  them  up  into  soluble 
material  to  restore  the  balance  and  supply 
a  store  of  energy  for  the  active  dissolved 
colloids  to  utilize  for  the  life-processes.  In 
this   way   slight   variations   in  environment 


EVOLUTION   OF   COLLOIDS      149 

determine  a  movement  upwards  or  downwards 
in  these  delicately  balanced  colloidal  com- 
pounds. 

Another  factor  in  the  chemical  reactions 
of  the  colloids  which  differs  from  that  of 
simple  inorganic  relationships  is  the  time  taken 
for  the  changes.  A  reaction  in  which  there 
is  a  great  change  of  energy  comparatively, 
for  a  small  amount  of  matter  altered,  runs 
very  swiftly.  Hydrogen  and  oxygen  unite 
to  form  water  with  a  practically  instantaneous 
explosion,  and  then  all  is  over  and  the  system 
is  inert.  A  moment  of  fierce  activity  followed 
by  absolute  rest.  But  in  colloidal  reactions, 
there  is  slow  movement  of  the  reaction  for 
days.  In  many  cases  it  is  never  complete, 
and  slight  changes  acting  on  the  system  can 
send  it  slowly  pulsating  up  and  down  about 
an  equilibrium  point. 

Such  changes  are  seen  even  in  inorganic 
colloids,  such,  for  example,  as  colloidal  silicic 
acid,  as  studied  by  Graham.  Silicic  acid  as 
ordinarily  obtained,  readily  gives  up  water 
and  forms  silica,  of  which  flint  and  sand  are 
composed.  This  substance,  needless  to  say, 
is  insoluble  in  water,  but  if  treated  with  strong 
alkali  it  forms  alkaline  silicates.  An  example 
of  such  is  sodium  silicate,  better  known  in 
solution  in  water  as  water  glass,  now  used 


150    ORIGIN  AND  NATURE  OF  LIFE 

somewhat  extensively  for  commercial  preser- 
vation of  eggs.  If  dilute  acid  be  added  cau- 
tiously to  this  substance  silicic  acid  in  a 
water-soluble  form  is  produced.  If  a  solution 
of  this  silicic  acid  be  placed  in  a  tube  made 
of  parchment  paper  (such  as  is  used  for  cover- 
ing jam-pots),  and  the  tube  be  suspended  in 
a  stream  of  running  water,  the  solution  may 
practically  be  freed  from  the  excess  of  acid 
used  for  its  manufacture  and  from  other 
impurities. 

This  was  the  method  by  which  Graham 
first  prepared  colloidal  silicic  acid,  and  by 
somewhat  similar  methods,  he  also  prepared 
a  large  number  of  other  inorganic  colloids 
in  clear  solution,  and  demonstrated  that  so 
far  from  being  exceptional  amongst  inorganic 
molecules,  the  colloidal  state  is  one  of  frequent 
occurrence. 

Such  colloidal  solutions  of  inorganic  bodies 
exhibit  all  the  delicate  properties  described 
above,  in  regard  to  coagulation,  etc. 

Graham  showed  that  the  silicic  acid  solution 
behaved  in  all  its  chemical  properties  as  if 
it  had  a  multi-molecule,  consisting  of  about 
sixty  molecules  instead  of  one,  united  into 
one  chemical  unit. 

It  still  behaved  as  an  acid,  but  a  given 
weight  of  it  only  required  about  one-sixtieth 


EVOLUTION   OF   COLLOIDS      151 

part  of  the  proper  amount  of  alkali  to  neutra- 
ize  it,  which  it  would  have  needed,  if  supposed 
to  be  composed  of  mono-molecules. 

The  huge  molecules  were  unable  to  pass 
through  the  parchment  paper  in  the  method 
of  separation  mentioned  above,  although  the 
acid  and  other  crystalloids  had  passed  through 
readily.  This  is  a  general  method  of  separa- 
tion of  colloids  and  crystalloids.  A  colloid 
in  solution  is  unable  to  penetrate  a  film  of  a 
hydrogel  of  another  colloid  placed  in  its  way. 
The  living  cell  makes  great  use  of  this  property 
by  possessing  such  a  film.  Inside  the  film 
of  hydrogel  it  holds  dissolved  colloids  or 
hydrosols  so  constituted  that  they  can  unite 
with  certain  crystalloids  (such  as  the  dissolved 
food-constituents,  amino  acids,  sugars,  fatty 
acids,  glycerine,  etc.).  The  hydrosols  are 
kept  within  the  cell  by  the  hydrogel  membrane 
and  the  crystalloids  diffuse  in.  Once  within 
they  are  either  broken  down  by  the  hydrosols 
to  yield  energy,  or  built  up  into  their  substance 
as  described  above.  This  relieves  pressure 
within  and  more  crystalloid  diffuses  in. 
Certain  inorganic  salts  also  combine  with  the 
hydrosols  of  the  cell,  and  so  accumulate 
preferentially  within  it,  such,  for  example, 
as  potassium  and  phosphates. 

This    property    of    indiffusibility    of    the, 


152   ORIGIN  AND  NATURE  OF  LIFE 

colloids  was  also  suggested  by  Graham  as  a 
method,  called  dialysis,  of  separating  colloids 
from  crystalloids  for  analytical  purposes.  For 
example,  such  a  crystalloid  as  strychnine 
can  easily  be  separated  from  proteins  and 
other  colloids,  in  the  mixed  contents  of  the 
stomach,  when  investigations  are  being  con- 
ducted in  a  case  of  supposed  poisoning,  and 
so  minimal  amounts  may  be  detected  in  a 
mixture  that  looks  at  first  sight  a  hopeless 
mess  to  analyze. 

In  many  important  industrial  processes 
this  property  is  now  employed,  and  it  is  one 
of  the  most  important  of  the  colloidal  pro- 
perties from  both  theoretical  and  practical 
points  of  view. 

When  a  solution  of  colloidal  silica  separated 
from  admixed  crystalloids  by  prolonged 
dialysis  is  examined,  it  is  a  perfectly  clear 
and  very  limpid  body,  which  remains  so  for 
some  days,  but  very  slowly  it  undergoes  the 
process  of  coagulation  and  sets  into  a  clear, 
slightly  opalescent,  jelly. 

Graham's  researches  were  published  in 
1862-4,  and  even  at  that  early  date  he  had 
realized  the  importance  to  the  physiologist 
of  the  study  of  the  properties  of  his  new-found 
bodies,  for  colloids,  as  he  says,  form  the 
active  part  of  all  living  cells.     Thus  he  states 


EVOLUTION   OF   COLLOIDS      153 

that  fat  might  be  carried  in  the  tissues  in 
invisible,  apparently  soluble  form  in  union 
with  the  colloidal  proteins.  The  carriage  of 
fat  about  the  body  was  long  a  puzzle  to  the 
physiologist,  for  it  is  insoluble  in  aqueous 
solutions,  and  hence  ought  to  have  been 
easily  traced,  but  its  appearances  and  dis- 
appearances in  many  tissues  without  being  seen 
in  transit,  formed  a  perplexing  conundrum. 
Recent  work  on  fatty  changes  and  degenera- 
tions has  demonstrated  the  exact  truth  of 
Graham's  remark  made  a  generation  earlier. 
In  our  present  concepts,  the  colloid  of  the  cell 
possesses  both  fat  and  carbohydrate  dissolved 
and  united  to  protein,  and  forming  a  mobile 
colloidal  whole,  in  which  chemical  oscillations 
are  ever  occurring  and  new  products  being 
elaborated.  Carbohydrate  and  fat  are  equally 
indispensable  with  protein  for  the  maintenance 
of  life.  If  absent  from  the  food  they  are 
manufactured  from  amino  acids  by  the  living 
complex  of  the  cell. 

Graham  also  points  out  that  just  as  ferments 
during  digestion  disrupt  and  dissolve  proteins, 
such  as  white  of  egg,  so  alkali  dissolves  gela- 
tinized silica  acid,  by  disrupting  the  colloidal 
union  of  its  aggregates,  and  he  calls  his  gela- 
tinized colloids  pectized  colloids,  and  their 
process  of  solution  "  peptization,"  on  account 


154    ORIGIN  AND  NATURE  OF  LIFE 

of  this  analogy.  The  solvent  action  is  not 
one  of  complete  passage  to  the  crystalloidal 
form,  for  the  amount  of  alkali  necessary  to 
give  a  clear  peptized  solution  is  only  a  small 
percentage  of  the  calculated  amount  for 
neutralizing  all  the  silicic  acid  into  mono- 
molecules.  The  solution  of  the  gelatinized 
mass  is  due  to  a  partial  disruption  only,  with 
formation  of  smaller  colloidal  complexes. 
Each  of  these  complexes  is  held  in  solution 
by  one  or  more  active  crystalloidal  molecules 
of  the  alkali,  the  two  components  so  forming 
what  is  now  termed  a  crystallo-colloid. 
Such  crystallo-colloids  play  a  most  important 
part  in  the  life-work  of  the  living  cells. 
Proteins  have  hitherto  been  spoken  of  in  this 
volume  as  if  they  were  wholly  organic,  but  it 
has  long  been  known  that  proteins  as  they 
occur  naturally  can  never  be  obtained  without 
an  appreciable  amount  of  inorganic  matter. 
This  inorganic  matter,  chemists  for  long 
agreed  to  regard  as  an  impurity,  and  so  it  was 
called  "  protein  ash."  It  varies  from  a  half 
to  two  per  cent,  in  the  majority  of  proteins, 
and  was  invariably  regarded  as  a  nuisance 
by  earlier  physiological  chemists,  who  were 
striving  after  pure  products  of  constant 
composition.  It  did  not  fit  in  with  their 
scheme    of    things.     Modern    research    has, 


EVOLUTION    OF    COLLOIDS      155 

however,  shown  that  this  is  an  intrinsic 
part  of  the  proteins,  a  central  part  of  the 
whole  scheme,  without  which  activity  is  lost 
and  the  whole  mass  becomes  inert  and  dead. 
Ash-free  protein,  the  dream  of  the  earlier 
workers,  is  protein  no  longer  in  any  of  its 
essential  properties.  An  isolated  beating 
heart  from  which  certain  inorganic  salts  are 
washed  out  by  an  irrigating  stream  containing 
none  of  them,  soon  ceases  to  contract,  but  on 
restoring  these  inorganic  salts  the  heart  soon 
starts  automatically  to  work  once  more. 
The  same  can  be  proved  for  all  living  cells, 
the  appropriate  inorganic  crystalloids  must 
be  there,  and  present  in  definite  amount 
neither  too  little  nor  too  much,  so  as  to 
form  the  crystallo-colloids,  or  the  living 
cells  cease  operations  and  soon  thereafter 
perish. 

This  fundamental  relationship  of  inorganic 
and  organic  constituents  is  interesting  in  view 
of  the  evolution  of  the  organic  world  from  the 
inorganic.  It  forcibly  calls  to  mind  that  law 
of  the  evolution  of  the  higher  animal  which 
records  that  the  higher  embryo  passes  rapidly 
through  some  of  the  lower  forms  of  its  ancient 
ancestors  in  its  individual  evolution.  So, 
probably,  living  matter  is  still  unable  to 
dispense   with   those   simple   inorganic   sub- 


UL 


156   ORIGIN  AND  NATURE  OF  LIFE 

stances  by  means  of  which  it  first  arose  from 
inorganic  nature. 

Whatever  may  be  the  reason,  simple 
inorganic  salts  are  indispensable  in  all  living 
cells,  and  exist  in  union  with  the  proteins 
forming  crystallo-colloids. 

The  peculiar  energy  properties  of  colloidal 
solutions  and  the  bearing  of  such  proper- 
ties upon  the  life-processes  were  clearly 
expressed  by  Graham,  who  writes,  "  Their 
peculiar  physical  aggregation  with  the  chemi- 
cal indifference  referred  to,  appears  to  be 
required  in  substances  that  can  intervene 
in  the  organic  processes  of  life.  The  plastic 
elements  of  the  animal  body  are  found  in 
this  class.  As  gelatin  appears  to  be  its  type, 
it  is  proposed  to  designate  substances  of  the 
class  as  colloids,  and  to  speak  of  their  peculiar 
form  of  aggregation  as  the  colloidal  condition 
of  matter.  Opposed  to  the  colloidal  is  the 
crystalloidal  condition.  Substances  affecting 
the  latter  form  will  be  classed  as  crystalloids. 
The  distinction  is  no  doubt  one  of  intimate 
molecular  constitution.  "  Although  chemi- 
cally inert  in  the  ordinary  sense,  colloids 
possess  a  compensating  activity  of  their  own, 
arising  out  of  their  physical  properties. 
While  the  rigidity  of  the  crystalline  structure 
shuts  out  external  impressions,  the  softness 


EVOLUTION    OF    COLLOIDS      157 

of  the  gelatinous  colloid  partakes  of  fluidity, 
and  enables  the  colloid  to  become  a  medium 
for  liquid  diffusion,  like  water  itself." 

"  Another  and  eminently  characteristic 
quality  of  colloids  is  their  mutability.  Their 
existence  is  a  continued  metastasis.  A  colloid 
may  be  compared  in  this  respect  to  water 
while  existing  liquid  at  a  temperature  under 
its  usual  freezing-point,  or  to  a  supersaturated 
saline  solution.  Fluid  colloids  appear  to 
have  always  a  pectous  modification ;  and 
they  often  pass  under  the  slightest  influence 
from  the  first  into  the  second  condition." 

"  The  colloid  is,  in  fact,  a  dynamical  state 
of  matter  ;  the  crystalloidal  being  the  statical 
condition.  The  colloid  possesses  Energia. 
It  may  be  looked  upon  as  the  probable 
primary  source  of  the  force  appearing  in  the 
phenomena  of  vitality.  To  the  gradual 
manner  in  which  colloidal  changes  take  place 
(for  they  always  demand  time  as  an  element) 
may  the  characteristic  protraction  of  chemico- 
organic  changes  also  be  referred." 

The  importance  of  these  slow  energy 
changes  in  colloids  referred  to  in  the  above 
extract  by  Graham,  half  a  century  ago,  and 
the  capability  of  their  alteration  and  travel 
in  new  directions  on  account  of  small  changes 
in  the  crystalloidal  environment,  so  giving 


158    ORIGIN  AND  NATURE  OF  LIFE 

rise  to  phasic  variations  in  the  energy  processes 
of  the  living  cell,  are  only  now  somewhat 
tardily  receiving  that  attention  and  further 
study  which  they  so  richly  deserve.  Many 
of  the  hidden  wonders  of  cell  life  undoubtedly 
are  clustered  around  the  relationship  of 
colloid  and  crystalloid. 

Variations  in  minute  detail  of  colloidal 
arrangement  in  itself,  and  in  relationship  to 
dissolved  pabulum  in  the  shape  of  organic 
and  inorganic  crystalloids,  lie  at  the  root  of 
the  varying  activities  of  the  cells,  and  of  all 
physiological  and  pathological  changes. 


CHAPTER   VII 

THE   ORIGIN   OF   LIFE 

The  origin  of  life  is  one  of  those  primeval 
questions  that  have  agitated  the  human  mind 
throughout  the  ages.  Some  system  of  creation 
has  formed  a  basic  part  of  every  religious 
creed  in  all  lands,  and  the  progress  and  ad- 
vancement of  a  people  at  any  given  period 
are  reflected  in  their  beliefs  on  this  subject. 
The  general  state  of  scientific  thought  and 
knowledge  at  different  times  is  also  indicated 


THE   ORIGIN   OF   LIFE  159 

by  the  writings  of  the  contemporary  philoso- 
phers upon  this  theme,  and  the  growth  of 
enlightenment  from  age  to  age  can  be  traced 
in  the  changing  beliefs  upon  the  subject. 
The  most  beautiful  tales  of  the  mythologies  of 
ancient  civilizations  cluster  round  this  subject 
so  mysteriously  ingrained  in  the  nature  of  the 
mind,  and  great  truths  have  been  handed  down 
disguised  "in  those  common  legends  of  all  races, 
which  deal  with  the  origin  of  man  upon  the 
earth.  Fascinating  as  are  many  of  these 
attempts  of  the  imagination  and  inner  con- 
sciousness to  evolve  such  a  scheme  of  organic 
creation  as  might  enable  man  more  nobly  to 
worship  this  great  mystery,  none  of  them 
appeal  to  the  educated  imagination  so  power- 
fully as  the  actual  picture  which  modern 
science  is  revealing  to  our  eyes,  as  a  new  and 
natural  revelation  of  the  Infinite. 

The  mystery  is  still  there,  and  ever  will 
remain,  but  the  steps  by  which  the  beauties 
of  creation  were  developed,  and  are  still 
developing,  are  becoming  visible;  and  the 
vision  only  fills  every  thoughtful  mind  with 
greater  reverence  for  a  power  and  a  glory 
more  fully  revealed.  No  single  creative  act 
could  fill  the  mind  with  half  the  awe  and 
admiration  evoked  by  this  spectacle,  in  the 
heavens    and    upon    earth,    of    continuous 


160    ORIGIN  AND  NATURE  OF  LIFE 

evolution  of  wonder  upon  wonder.  Scientific 
myth  and  religious  myth  of  past  ages  are 
alike  to  be  honoured  and  preserved  as  the 
best  attempts  of  the  knowledge,  or  science, 
of  past  ages  to  look  up  to  this  mystery,  to 
understand  it,  and  to  worship  the  highest. 
It  becomes  no  man  to  scoff  at  these  things, 
and  the  labourer  in  science  who  gets  so  lost 
in  mechanical  detail  that  he  has  no  mind  left 
for  the  grandeur  of  the  whole  design  for  which 
detail  only  forms  the  substructure,  could  he 
but  appreciate,  would  gain  in  inspiration  and 
incentive  from  a  sympathetic  touch  of  faith 
in  that  spirit  which  breathes  through  the 
whole  universe,  and  gives  life  to  his 
mechanisms. 

Those  who  are  inclined  to  think  that  the 
search  after  the  mystery  of  life  is  illusory 
and  leads  no  whither,  or  to  no  practical  goal, 
have  not  studied  the  history  of  scientific 
advance  with  clear  vision.  The  problem  is 
not  purely  a  philosophical  one  ;  on  the  other 
hand,  it  is  an  eminently  practical  and  experi- 
mental one  in  itself,  and  the  richest  harvest 
that  ever  biological  study  yielded  to  mankind 
arose  incidentally  to  an  enquiry  into  the 
origin  of  life. 

Just  as  the  search  for  the  philosopher's 
stone  that  was  to  transmute  the  baser  metals 


THE    ORIGIN    OF    LIFE  161 

into  gold,  led  through  alchemy  to  the  founda- 
tions of  modern  chemistry,  and  to  a  richer 
reward  than  the  long-sought  stone,  and  as 
the  vain  pursuit  of  the  elusive  elixir  vitce, 
that  was  to  renew  youth  and  vigour  and  give 
unending  life  at  the  prime,  merged  into  the 
beginnings  of  scientific  medicine;  so  the 
enquiry  into  spontaneous  generation,  or  the 
origin  of  life,  opened  up  the  whole  of  our 
modern  knowledge  of  the  causation  of  disease 
through  the  discoveries  of  Pasteur,  and 
onward  beyond  that  laid  the  broad  founda- 
tions for  the  wonderful  developments  of 
modern  surgery  which  arose  from  the  noble 
lifework  of  Lister.  Millions  of  lives  have 
been  saved,  and  untold  misery  and  suffering 
averted,  by  practical  discoveries  which  arose 
from  apparently  purely  philosophical  enquiries 
dealing  with  theories  which  might  have  been 
dismissed  as  chimerical. 

If  the  ubiquitous  practical  man  were  asked 
to  mention  the  most  magnificent  of  the 
discoveries  of  Pasteur,  he  would  probably 
name  the  proof  on  which  modern  sanitation 
is  based,  that  infectious  diseases  were  due 
to  micro-organisms.  Brilliant  and  far-reach- 
ing as  this  discovery  is,  it  will,  however,  be 
surpassed  in  the  judgment  of  later  generations 
by  something  which  the  great  French  savant 


162    ORIGIN  AND  NATURE  OF  LIFE 

probably  did  not  even  realize  that  he  had 
achieved,  and  that  is  the  giving  of  a  new  basis 
for  the  enquiry  into  the  origin  of  life,  by 
supplying  proper  limitations  and  a  new 
starting  point. 

Pasteur,  as  the  result  of  years  of  patient 
labour,  proved  with  the  clearness  of  a  scientific 
demonstration,  that  the  views  of  his  opponents 
regarding  spontaneous  generation  were  purely 
mythical.  The  opposition  which  met  his 
views  can  only  be  compared  to  the  storm 
which  met  Darwin  and  his  supporters  over 
evolution,  but  patiently  Pasteur  advanced, 
proving  point  after  point  with  irresistible 
experiment  and  logical  conclusion,  and  in  the 
end  he  triumphed. 

A  blind  alley  in  the  enquiry  as  to  the  origin 
of  life  was  thus  closed  for  ever,  and  one  with 
most  alluring  prospects,  which  had  tempted 
the  minds  of  philosophers  and  experimenters 
for  long  ages. 

Although  it  was  not  appreciated,  this  was 
a  great  contribution  towards  the  enquiry. 
At  first  sight,  the  discovery  seemed  to  close 
the  quest  for  ever,  for  this  path  was  the  only 
one  trodden  for  centuries  by  countless  en- 
quirers, and  it  is  easier  to  follow  old  ways 
than  to  find  new  ones. 

It  required  some  years  of  fallowness,  during 


THE    ORIGIN    OF   LIFE  163 

which  the  great  practical  applications  of 
Pasteur's  discoveries  monopolized  attention, 
before  the  main  quest  could  begin  to  be 
thought  of  in  the  light  of  Pasteur's  investi- 
gations. 

The  great  merit  of  Schafer's  Presidential 
Address  (1912)  to  the  British  Association  at 
Dundee  lies  in  this,  that  it  has  once  more 
centred  the  attention  of  the  scientific  world 
upon  the  main  inquiry,  and  marked  it  out 
as  a  problem  that  may  be  solved  and  one 
demanding  experimental  enquiry. 

Life  probably  arose  as  a  result  of  the 
operation  of  causes  which  may  still  be  at 
work  to-day  causing  life  to  arise  afresh. 
Although  Pasteur  has  conclusively  proven 
that  life  did  not  originate  in  certain  ways, 
that  does  not  exclude  the  view  that  it  arose 
in  other  ways.  The  problem  is  one  that 
demands  thought  and  experimental  work, 
and  is  not  an  exploded  chimera.  Therein 
lies  the  value  of  Schafer's  contribution  to  the 
question,  and  it  is  a  most  refreshing  and 
valuable  one. 

Before  approaching  the  modern  aspects  of 
the  problem,  it  may  be  of  historical  interest 
to  enquire  what  was  the  position  evacuated 
as  a  result  of  Pasteur's  researches. 

The    question    of    spontaneous    generation 


164    ORIGIN  AND  NATURE  OF  LIFE 

had  undergone  many  vicissitudes  before 
Pasteur's  time ;  it  had  been  affirmed  or 
denied  by  philosopher,  naturalist,  or  poet 
from  age  to  age. 

The  great  Greek  philosopher,  Thales,  traced 
the  origin  of  life  in  water,  and  Aristotle 
stated  the  remarkable  paradox  that  dry 
bodies  engendered  animals  when  they  became 
damp,  and  moist  bodies  produced  a  like 
effect  when  they  dried. 

Van  Helmont,  a  deservedly  famous  physicist 
and  chemist  of  the  sixteenth  century,  was  a 
great  believer  in  spontaneous  generation, 
and  stated  that  even  mice  could  be  spontan- 
eously generated  by  the  simple  device  of 
placing  some  dirty  linen  in  a  receptacle, 
together  with  a  few  grains  of  wheat  or  a  piece 
of  cheese.  The  same  philosopher's  plan  for 
engendering  scorpions  is  naive  and  amusing  : 
"  Scoop  out  a  hole  in  a  brick.  Put  into  it 
some  sweet  basil,  crushed.  Lay  a  second 
brick  upon  the  first  so  that  the  hole  may  be 
perfectly  covered.  Expose  the  two  bricks 
to  the  sun,  and  at  the  end  of  a  few  days  the 
smell  of  the  sweet  basil,  acting  as  a  ferment, 
will  change  the  herb  into  real  scorpions." 

A  strange  metamorphosis  was  that  announ- 
ced by  an  Italian,  Buonanni,  who  found  that 
some  rotten  timber  which  he  rescued  from 


THE    ORIGIN    OF   LIFE  105 

the  sea,  produced  worms,  which  engendered 
butterflies,  and  the  butterflies,  strangest  of 
all,  became  birds.  But  it  was  also  from 
Italy  that  the  first  critical  experimental 
observation  came  :  Redi,  a  poet  and  physician 
of  that  country,  clearly  demonstrated  that 
larvae  were  not  engendered  spontaneously  in 
decomposing  meat,  by  taking  the  simple 
precaution  of  placing  the  meat  in  a  wide- 
mouthed  bottle  and  covering  the  mouth  of 
the  bottle  with  gauze.  Flies  attracted  by  the 
odour,  deposited  their  eggs  on  the  gauze,  and 
Redi  showed  that  it  was  from  these  and  not  by 
spontaneous  generation  that  the  so-called 
worms  arose.  Valisneri,  another  Italian  scien- 
tist, gave  a  similar  demonstration  for  fruit 
grubs,  and  thus  the  basis  of  our  knowledge  of 
the  interesting  metamorphosis  of  insects  was 
laid.  Later  on,  that  great  physiologist,  the 
Abbe  Spallanzani,  after  the  advent  of  the 
microscope,  really  quite  clearly  proved  the 
fallacy  of  spontaneous  generation  by  experi- 
ments as  decisive  as  those  of  Pasteur  a  century 
later.  But  the  age  was  not  receptive,  nor  was 
the  ground  then  prepared  for  the  world  to 
understand  the  importance  of  the  discovery,  or 
take  that  lead  towards  the  knowledge  of  the 
causes  of  disease  which  in  the  hands  of 
Pasteur  resulted  from  his  discovery. 


166    ORIGIN  AND  NATURE  OF  LIFE 

The  work  of  Spallanzani  is  so  remarkably 
ingenious  for  the  age  in  which  it  was  performed 
and  has  been  so  overshadowed  by  later 
discoveries,  that  it  seems  just  to  quote  it 
briefly. 

The  experiments  of  Redi  and  Valisneri, 
mentioned  above,  had  refuted  the  grosser 
views  of  spontaneous  generation,  and  it  was, 
strange  to  say,  the  discovery  of  the  microscope 
towards  the  end  of  the  seventeenth  century, 
which  temporarily  rehabilitated  the  theory, 
at  least  for  microscopic  animalculse.  Armed 
with  the  new  instrument,  any  one,  in  a  day 
or  two,  could  easily  demonstrate  for  himself 
the  spontaneous  generation  of  microscopic 
eels  in  flour  or  vinegar,  or  produce  myriads 
of  different  and  interesting  live  creatures  in 
rain  water  kept  for  a  day  or  two  in  closed 
vessels,  or  in  a  simple  infusion  of  hay  or  other 
organic  material.  The  new  wonders  of  the 
microscope  awakened  enthusiasm  all  over 
the  scientific  world,  and  disputants  on  both 
sides  fought  and  argued,  for  and  against, 
spontaneous  generation,  and  religious  feeling 
was  invoked  on  both  sides.  To-day,  we  may 
be  inclined  to  smile  at  the  simple  arguments 
brought  forward  as  weighty  proofs,  but  it  is 
to  be  remembered  how  new  all  this  territory 
then    was,    how    little    orientation    any    one 


THE   ORIGIN   OF   LIFE         167 

possessed,  and  that  the  life-histories  of  these 
multitudinous  forms  of  microscopic  life  were 
not  then  elementary  biology  as  they  are  to-day. 
To  explain  the  appearance  of  these  living 
organisms,  an  English  cleric,  Needham,  and 
the  great  naturalist,  Buff  on,  evolved  the  theory 
that  a  force,  called  productive  or  vegetative 
force,  existed,  which  was  responsible  for  the 
production  of  organized  beings.  Buff  on  elabo- 
rated the  theory  that  there  were  certain 
unchangeable  parts  common  to  all  living 
things.  These  ultimate  organic  constituents 
he  supposed  capable  of  taking  various  moulds 
or  shapes  which  constituted  the  various 
living  creatures.  After  death,  these  ultimate 
constituent  parts  were  supposed  to  be  set 
free  and  become  very  active.  Uniting  with 
one  another  and  with  other  particles  they 
formed  swarms  of  microscopic  creatures  such 
as  the  microscope  revealed,  or  even  produced 
earthworms  and  larger  fungi. 

Needham  took  putrescible  organic  matter 
and  enclosed  it  in  vessels  which  he  placed 
upon  hot  ashes  to  destroy  any  existing 
animalculse ;  yet,  later,  in  these  fluids,  he 
found  animalculse  which  were  not  observed 
there  in  the  beginning. 

It  was  in  refutation  of  this  work  that  the 
Abbe  Spallanzani  carried  out  the  remarkable 


168    ORIGIN  AND  NATURE  OF  LIFE 

series  of  experiments  mentioned  above.  He 
suspected  two  defects  in  Needham's  work, 
just  the  same  as  those  which  Pasteur  dis- 
covered in  the  proofs  of  his  opponents  a 
century  later,  namely,  insufficient  sterilization 
by  heat,  and  infection  during  the  experiment 
with  living  seed  carried  from  outside,  for 
Needham  had  only  closed  his  incubation 
vessels  with  cork  stoppers. 

At  that  early  date  Spallanzani  actually 
repeated  the  work  in  hermetically  sealed 
vessels,  and  used  sterilization  by  boiling  for 
one  hour.  He  writes,  "  I  used  hermetically 
sealed  vessels.  I  kept  them  for  an  hour  in 
boiling  water,  and  after  opening  and  examining 
their  contents  after  a  reasonable  interval,  I 
found  not  the  slightest  trace  of  animalculae, 
though  I  had  examined  with  the  microscope 
the  infusions  from  nineteen  different  vessels." 
Such  work  as  this  accomplished  in  the  middle 
of  the  eighteenth  century  deserves  a  prominent 
place  for  its  author  in  scientific  history. 
The  same  observer,  it  may  be  mentioned,  also 
discovered  the  antiseptic  action  of  the  gastric 
juice. 

Needham's  reply  was  that  the  prolonged 
boiling  had  altered  the  character  of  the 
infusion  so  that  it  was  unable  to  engender 
life.     The  witty  pen  of  that  master  of  satire, 


THE   ORIGIN   OF  LIFE         ica 

Voltaire,  produced  in  1769,  a  tract  in  which 
he  laughed  to  scorn  the  operations  of  the 
English  cleric  who  had  engendered  eels  in  the 
gravy  of  boiled  mutton.  He  describes  as  a 
ridiculous  mistake  "the  unfortunate  experi- 
ments of  Needham  so  triumphantly  refuted 
by  Spallanzani."  Elsewhere  he  wittily  re- 
marks, "It  is  strange  that  men  should  deny 
a  Creator  and  yet  attribute  to  themselves 
the  power  of  creating  eels." 

All  the  wit  of  Voltaire  could  not,  however, 
obtain  for  the  work  of  Spallanzani  that 
credence  which  it  so  palpably  deserved,  and 
the  subject  remained  a  source  of  philosophical 
discussion. 

The  last  stage  was  opened  by  a  paper 
which  was  sent  to  the  Academie  des  Sciences 
in  1858,  by  M.  Pouchet,  a  French  scientist 
of  high  standing.  The  new  departure  claimed 
by  Pouchet  was  that,  exercising  the  greatest 
care  to  prevent  any  error  creeping  in,  he 
had  been  able  to  engender  living  micro- 
organisms, plant  and  animal,  in  culture  media 
exposed  only  to  artificial  air  or  oxygen. 
The  point  was  that  such  organisms  appeared 
in  a  medium  absolutely  free  from  atmospheric 
air,  and  in  which,  as  a  consequence,  no  germ 
could  possibly  have  arrived  as  an  air-borne 
particle. 


170    ORIGIN  AND  NATURE  OF  LIFE 

This  paper  attracted  universal  attention, 
and  stimulated,  on  the  part  of  Pasteur, 
four  years  of  incessant  labour,  crowded  with 
ingenious  experiments,  all  planned  towards 
one  common  end.  He  showed  that  sterilized 
cultures  always  became  infected  when  exposed 
to  air  ;  that  properly  filtered  or  sterilized  air 
never  caused  infection ;  that  Alpine  air 
almost  free  from  germs  scarcely  ever  produced 
a  growth  of  organisms  ;  that  city  air  nearly 
always  produced  contamination  ;  and  that 
in  absence  of  added  germs  from  without, 
culture  media  remained  sterile  for  years. 
The  sources  of  error  in  the  work  of  his  oppon- 
ents were  elucidated,  and  their  contrary 
results  explained  on  such  grounds.  So,  step 
by  step,  each  logically  thought  out,  Pasteur 
established  his  position. 

Passing  on  to  the  applications  of  this  great 
demonstration  of  the  impossibility  of  the 
spontaneous  birth  of  germs  in  such  culture 
media,  Pasteur  himself  in  the  subsequent 
years  of  his  life  discovered  the  causative 
germ  of  several  important  diseases.  Similar 
labours  were  also  taken  up  by  hundreds  of 
willing  hands,  and  to-day  the  whole  vast 
science  of  bacteriology,  with  its  immense 
applications  in  modern  medicine,  surgery  and 
sanitation  rests  wholly  upon  this  discovery, 


HOW   LIFE    CAME    TO   EARTH    171 

a  discovery  made,  it  will  be  observed,  in 
studying  the  question  of  the  origin  of  life. 
Vast  industries  concerned  in  the  preparation 
and  preservation  of  food,  and  in  the  scientific 
fertilization  of  land,  are  also  based  on  this 
unique  discovery. 

Yet  all  this  by  no  means  settles  in  the 
negative  the  question  of  the  spontaneous 
origin  of  life,  it  only  proves  clearly  that  life 
cannot  arise  under  a  particular  set  of  con- 
ditions, and  so  narrows  the  issue  and  leads 
onward  to  new  experimental  questions  which 
may  even  be  as  fruitful  as  the  old  ones. 


CHAPTER    VIII 

HOW  LIFE   CAME   TO   EARTH 

When  it  became  settled  that  life  did  not  arise 
spontaneously  on  the  earth,  in  the  particular 
way  that  had  been  supposed  from  dead  organic 
matter,  the  minds  of  scientists  turned  towards 
the  explanation  of  the  course  by  which  it 
had  made  its  advent  upon  our  planet  from 
elsewhere. 

One    hypothesis    which    appears    to  have 
sprung   up    spontaneously   in   many    minds, 


172    ORIGIN  AND  NATURE  OF  LIFE 

with  slight  variants  in  each  case,  is  that 
known  as  the  theory  of  cosmozoa  or  pan- 
spermia. According  to  all  the  many  versions, 
life  did  not  spontaneously  arise  on  the  earth, 
but  was  carried  to  it  from  some  other  world 
where  it  already  was  existent,  either  by 
origin  there,  or  by  similar  carriage.  The 
various  forms  of  this  belief  (for  it  cannot  be 
called  more  in  lack  of  all  experimental  evi- 
dence) differ  as  to  whether  life  was  coeval 
with  matter  and  had  existed  for  ever,  or 
whether  it  was  once  created  on  a  planet 
and  ever  afterwards  disseminated.  Helmholtz 
puts  the  problem  clearly  when  he  says,  "  I 
cannot  contend  against  one  who  would 
regard  this  hypothesis  as  highly  or  wholly 
improbable.  But  it  appears  to  me  to  be 
a  wholly  correct  scientific  procedure,  when 
ail  our  endeavours  to  produce  organisms  out 
of  lifeless  substance  are  thwarted,  to  question 
whether,  after  all,  life  has  ever  arisen,  whether 
it  may  not  be  even  as  old  as  matter,  and 
whether  its  germs,  passed  from  one  world  to 
another,  may  not  have  developed  where  they 
found  favourable  soil.  The  true  alternative 
is  evident ;  organic  life  has  either  begun  to 
exist  at  some  one  time,  or  has  existed  from 
eternity." 

Lord    Kelvin    held    similar    views    before 


HOW   LIFE    CAME    TO   EARTH    173 

Helmholtz,  and  definitely  expresses  the  opinion 
that,  "  Dead  matter  cannot  become  living 
without  coming  under  the  influence  of  matter 
previously  living.  This  seems  to  me  as  sure 
a  teaching  of  science  as  the  law  of  gravitation." 

On  the  other  hand,  the  great  botanist, 
Nageli,  taught,  "  If  in  the  physical  world  all 
things  stand  in  causal  connection  with  one 
another,  if  all  phenomena  proceed  along 
natural  paths,  then  organisms,  which  build 
themselves  up  from  and  finally  disintegrate 
into  the  substances  of  which  inorganic  nature 
consists,  must  have  originated  primitively 
from  inorganic  compounds.  To  deny  spon- 
taneous generation  is  to  proclaim  a  miracle." 

Not  only  do  the  adherents  to  the  several 
variants  of  this  story  of  the  advent  of  life 
upon  the  earth  from  space,  differ  as  to  whether 
life  has  lasted  from  all  time,  or  was  subse- 
quently created,  there  are  many  variations 
as  to  how  it  came.  Some,  such  as  Kelvin 
and  Helmholtz,  regard  it  as  carried  by  meteor- 
ites, or  fragments  of  planets  that  had  borne 
life  when  they  went  to  destruction  ;  others, 
such  as  Richter,  or  more  recently  Arrhenius, 
postulate  an  impalpable  dust  or  panspermia 
scattered  through  all  space  and  borne  from 
the  atmosphere  of  one  planet  to  that  of 
another.     Kelvin  may  be  taken  as  the  ex- 


< 


174    ORIGIN  AND  NATURE  OF  LIFE 

ponent  of  the  former,  and  Arrhenius  as  that 
of  the  latter  view. 

Kelvin,  in  his  address  to  the  British  Associa- 
tion at  Edinburgh  in  1871,  put  the  proposition 
thus  :  "  When  two  great  masses  come  into 
collision  in  space,  it  is  certain  that  a  large 
part  of  each  is  melted  ;  but  it  seems  also 
quite  certain  that  in  many  cases  a  large 
quantity  of  debris  must  be  shot  forth  in  all 
directions,  much  of  which  may  have  experi- 
enced no  greater  violence  than  individual 
pieces  of  rock  experience  in  a  landslip  or  in 
blasting  by  gunpowder.  Hence  and  because 
we  all  confidently  believe  that  there  are  at 
present,  and  have  been  from  time  immemorial, 
many  worlds  of  life  beside  our  own,  we  must 
regard  it  as  probable  in  the  highest  degree 
that  there  are  countless  seed-bearing  meteoric 
stones  moving  about  in  space.  If  at  the 
present  instant  no  life  existed  upon  this 
earth,  one  such  stone  falling  upon  it  might, 
by  what  we  blindly  call  natural  causes,  lead 
to  its  becoming  covered  with  vegetation." 

The  view  of  Arrhenius  is  a  more  modern 
variation  ;  he  proceeds  from  the  known  facts 
of  bacteriology,  that  the  minutest  germs  of 
life  float  about  in  the  air,  many  of  them 
ultra-microscopic  in  magnitude.  These  minu- 
test germs  of  living  matter  may  be  carried 


HOW    LIFE    CAME    TO    EARTH    175 

to  the  upper  strata  of  an  atmosphere,  and  here 
come  under  the  influence  of  radiant  energy  of 
various  forms,  as  minute  dust  particles  may 
in  the  aurora  borealis,  for  example.  It  has 
been  shown  that  there  is  a  pressure  of  the 
light  waves  upon  such  particles,  which  is 
capable  of  giving  them  a  translatory  velocity 
in  a  vacuum,  similar  to  that  of  the  vanes  of 
Crookes'  radiometer  in  radiant  light  or  heat. 
It  is  only  necessary  to  assume  small  enough 
dimensions  of  the  germ  particles  to  achieve 
enormous  velocities.  Arrhenius  calculates, 
that  if  living  germs  were  carried  through  the 
ether  by  such  radiant  forms  of  energy,  the 
time  of  transit  from  our  earth  to  Mars  would 
only  be  twenty  days,  and  from  our  solar 
system  to  the  nearest  stellar  system  about 
nine  thousand  years. 

These  stellar  and  interstellar  hypotheses 
as  to  the  advent  of  life  upon  our  earth  cannot 
be  better  criticized  than  in  the  words  used 
by  Professor  Schafer  in  his  presidential 
address  to  the  British  Association,  Dundee, 
1912  : — "  But  the  acceptance  of  such  theories 
of  the  arrival  of  life  on  the  earth  does  not 
bring  us  any  nearer  to  a  conception  of  its 
actual  mode  of  origin;  on  the  contrary,  it 
merely  serves  to  banish  the  investigation  of 
the  question  to  some  conveniently  inaccessible 


176  ORIGIN  AND  NATURE  OF  LIFE 

corner  of  the  universe,  and  leaves  us  in  the 
unsatisfactory  position  of  affirming  not  only 
that  we  have  no  knowledge  as  to  the  mode  of 
origin  of  life — which  is  unfortunately  true — 
but  that  we  never  can  acquire  such  knowledge, 
which,  it  is  to  be  hoped,  is  not  true.  Knowing 
what  we  know,  and  believing  what  we  believe, 
as  to  the  part  played  by  evolution  in  the 
development  of  terrestrial  matter,  we  are, 
I  think  (without  denying  the  possibility  of 
the  existence  of  life  in  other  parts  of  the 
universe),  justified  in  regarding  these  cosmic 
theories  as  inherently  improbable — at  least 
in  comparison  with  the  solution  of  the  problem 
which  the  evolutionary  hypothesis  offers." 

It  has  been  seen  in  following  the  evolution- 
ary process,  step  by  step,  in  the  preceding 
chapters,  that  even  in  the  inorganic  world 
gigantic  molecules  can  be  built  up.  And 
that  as  molecular  complexity  increases,  and 
the  firmness  of  chemical  union  in  the  con- 
stituent parts  decreases,  a  delicate  mobile 
balance  becomes  established,  easily  destroyed 
but,  within  the  limits  of  its  stability,  capable 
of  oscillatory  energy  changes. 

Many  of  the  properties  of  the  molecules 
of  these  inorganic  colloids  approximate  to 
those  of  the  organic  colloids  found  in  living 
structures. 


HOW    LIFE    CAME    TO    EARTH    177 

The  whole  living  world  depends  upon  the 
building  up  of  the  energy  of  the  sunlight 
into  the  chemical  energy  of  these  organic 
colloids  which  constitute  living  structures. 
The  energy-transformer  is  the  green  cell  of 
the  plant,  and,  directly  or  indirectly,  the 
energy  of  all  that  lives,  in  the  present  stage 
of  evolution,  arises  from  this  one  source 
transmuted  by  this  one  transformer.  In  the 
vegetable  world  itself,  those  parts  of  the 
plant  which  are  not  green  possess  no  power 
of  building  up  energy  from  inorganic  sources. 
Such  parts  of  the  plant  obtain  organic  sub- 
stances as  a  source  of  energy  from  the  green 
parts,  and  the  colloids  of  such  parts  transform 
these  organic  compounds  into  others,  use  up 
their  energy  to  supply  power  for  their  own 
processes,  grow  in  size  by  transmuting  the 
supply  into  more  colloid,  or  form  reserve 
depots  intended  primarily  for  their  own  use, 
or  that  of  their  next  generation,  in  the  shape 
of  seeds,  fruits,  roots  and  tubers.  The 
bodies  of  the  plants,  including  their  reserves, 
are  eaten  by  animals,  and  are  broken  up  by 
the  digestive  juices  into  soluble  compounds 
which  can  again  be  built  up  into  colloids  by 
the  already  existing  colloids  of  the  living  cells 
of  the  animal.  Part  of  the  animal's  food  thus 
provided  is  oxidized  and  decomposed  back 


178    ORIGIN  AND  NATURE  OF  LIFE 

into  inorganic  substances  giving  out  on  the 
way  its  energy  for  the  life  processes  of  the 
animal ;  another  part  is  built  into  reserve 
chemical  energy  just  as  in  the  plant.  There 
are  also  whole  classes  of  plants  which  derive 
their  energy  just  like  animals,  by  living  on  the 
chemical  energy  of  other  plants,  or  upon 
animals.  Such  are  the  fungi  and  the  bacteria 
which  produce  disease  when  they  invade  the 
bodies  of  plants  or  animals,  or  those  which 
act  as  purifiers  by  decomposing  dead  plant 
or  animal  remains,  reducing  them  to  inorganic 
constituents,  and  so  completing  the  natural 
cycle.  In  the  process,  energy  is  set  free 
and  intermediately  used  by  the  bacteria 
flourishing  upon  the  dead  matter.  With  the 
exception  of  certain  supplies  of  energy 
utilized  from  winds  and  tides  and  waterfalls, 
all  the  energy  used  by  man  for  driving  human 
industries  and  concerns  comes  from  past  or 
present  sources  of  this  kind,  such  as  wood, 
coal,  petrol,  and  spirit  which  represent  the 
energy  of  the  sunlight  of  past  ages,  either 
immediate  or  remote. 

All  the  conveniences  and  luxuries  of  modern 
civilization  are  dependent  upon  energy  derived 
from  sunlight  through  the  agency  of  the 
transformer  contained  in  the  green  plant  cell. 

Now  the  green  colouring  matter,  which  acts 


HOW   LIFE    CAME    TO   EARTH    179 

as  an  intermediary  between  the  colloids  of  the 
green  cell  and  the  sunlight,  is  itself  an  exceed- 
ingly complicated  colloid  resembling,  in  many 
properties,  and  related  to,  the  colouring 
matter  of  the  blood  of  higher  animals.  With- 
out this  green  colouring  matter,  called  chloro- 
phyll, the  other  colloids  of  the  green  cell 
could  not  themselves  transmute  the  light 
energy  into  chemical  energy  for  the  main- 
tenance of  the  organic  world. 

When  a  plant  is  allowed  to  develop  in 
darkness,  its  leaves  are  colourless,  or  etiolated, 
as  it  is  termed,  no  pigment  is  developed,  and 
such  a  plant  can  build  up  no  fresh  organic 
material,  and  is  limited  to  that  which  it 
already  possesses.  It  has  been  allowed 
no  source  of  energy  in  the  sunlight,  and 
develops  no  mechanism  to  transmute  it. 
It  lives  and  develops  for  a  time  on  the  reserve 
of  organic  material  which  it  possesses,  and 
then  sickens  and  dies.  But  if,  before  this 
happens,  and  while  it  is  still  colourless,  it  is 
exposed  to  light,  then  the  organic  colloids 
in  its  parts  which  would  naturally  have 
been  green,  acted  upon  by  the  sunlight  undergo 
a  series  of  energy  transformations,  as  a 
result  of  which  the  body  called  chlorophyll 
is  developed.  This  begins  to  absorb  the  light 
energy,  and  takes  into  its  molecule  carbon- 


180   ORIGIN  AND  NATURE  OF  LIFE 

dioxide  and  water,  so  that  these  constitute 
parts  of  the  cell-colloid ;  oxygen  is  then  split  off 
and  the  carbon,  hydrogen  and  a  less  amount 
of  oxygen,  are  built  up  into  those  organic, 
energy-containing  bodies  described  in  a  pre- 
vious chapter.  These  bodies  are  built  up 
as  part  of  the  colloidal  complex  of  the  cell, 
until  an  excess  of  them  is  present,  when  they 
separate  out  as  reserve  carbohydrates,  fats 
and  proteins.  From  time  to  time  these  are 
dissolved  out  and  transported  in  the  plant 
sap  to  other  parts  of  the  plant,  to  supply 
energy  and  serve  as  materials  for  growth, 
and  the  plant  in  all  its  parts  goes  on  increasing 
and  growing.  This  organic  growth  afterwards 
serves  as  food  for  the  rest  of  the  world  of 
living  organisms. 

The  green  colouring  matter  wrested  from 
its  connection  with  the  living  colloid  of  the 
cell  in  which  it  occurs  is  almost  devoid  of 
power  to  produce  these  changes.  It  may 
be  readily  dissolved  out  by  solvents  such  as 
alcohol,  chloroform  or  benzene,  then  sus- 
pended in  water,  and  exposed  to  sunlight  in 
presence  of  those  inorganic  constituents  which 
in  its  normal  situation  it  transmutes  into 
organic  matter.  But  under  such  conditions 
an  infinitesimal  amount  only  of  one  of  the 
first  products  of  organic  synthesis  is  obtained 


HOW   LIFE   CAME   TO   EARTH    181 

and  the  process  soon  comes  automatically 
to  an  end. 

But  when  the  cell  colloid,  and  chlorophyll, 
and  the  inorganic  constituents  to  be  acted 
upon  are  built  up  into  one  chemical  whole, 
and  then  the  sunlight  plays  upon  this  complex 
colloid,  molecular  vibrations  and  energy  ex- 
changes are  initiated  which  cause  up -building 
of  organic  matter  and  transformation  from  one 
organic  substance  to  another.  Similarly,  in 
those  other  cells  of  plants  and  animals  which 
possess  no  green  transformer,  it  is  only  when 
the  organic  matter  (built  up  elsewhere  in  the 
green  cells  and  transported  to  the  colourless 
parts)  has  become  an  intrinsic  part  of  the 
colloidal  mass  of  the  new  cell,  that  it  can  be 
acted  upon  and  made  to  part  with  its  energy, 
or  used  to  form  living  matter.  A  molecule  of 
carbohydrate,  or  fat,  or  protein,  can  only 
form  an  integral  part  of  living  matter,  or  yield 
energy  to  living  matter,  after  it  has  been 
assimilated  into  the  colloidal  mechanism  of 
the  cell  and  chemically  constructed  into  its 
mass. 

The  substance  chlorophyll  is  itself  far 
too  complex  to  arise  as  a  first  step  from  in- 
organic matter  in  the  absence  of  life,  yet  as 
the  present  life-builder  of  the  world,  it  gives 
a  clue  as  to  what  ought  to  be  sought  for  in 


182   ORIGIN  AND  NATURE  OF  LIFE 

all  experimental  work  designed  to  discover 
a  bridge  over  the  interval  between  the 
inorganic  and  the  organic.  The  modern 
problem  of  spontaneous  generation  dawns 
upon  us  from  these  considerations. 

If  a  mental  picture  be  conjured  up  of  a 
world  in  which  there  is  as  yet  no  life,  but 
where  conditions  are  suitable  for  life  to  appear, 
it  is  evident  that  a  spontaneous  production 
of  such  a  thing  as  even  a  bacterium  or  other 
unicellular  organism,  would  by  no  means 
solve  the  problem,  the  new-born  cell  would 
have  no  organic  pabulum  and  must  perish. 
The  production  of  anything  so  complex  as 
chlorophyll  at  such  a  stage  is  unthinkable 
to  any  one  acquainted  with  the  subtle  con- 
tinuity of  all  nature.  In  such  a  world 
inorganic  colloids  must  first  develop,  and  in 
time  one  of  these  must  begin  to  evolve,  not  a 
living  cell,  not  anything  so  complex  as  a 
micro-coccus  or  a  bacillus,  not  even  a  complex 
protein,  carbohydrate,  or  fat,  but  some  quite 
simple  form  of  organic  molecule,  holding  a 
higher  store  of  chemical  energy  than  the 
simple  inorganic  bodies  from  which  it  was 
formed.  To  carry  out  such  a  function  the 
inorganic  colloid  must  possess  the  property 
of  transforming  sunlight,  or  some  other  form 
of    radiant    energy,    into    chemical    energy. 


HOW    LIFE    CAME    TO    EARTH    183 

Later,  such  simple  organic  compounds,  by 
the  agency  of  the  same  or  some  other  colloid, 
and  with  a  supply  of  external  energy,  would 
begin  to  condense  and  form  more  complex 
organic  molecules,  and  finally  complexes  of 
inorganic  and  organic  matter  would  come 
into  existence  as  crystallo-colloids.  In  this 
way  without  any  hiatus  life  would  be  led  up 
to,  and  inaugurated. 

The  search  for  such  an  inorganic  transformer 
is  not  without  a  hopeful  outlook.  It  is 
already  known  that  the  element  selenium 
and  other  inorganic  bodies,  are  affected  by 
light.  The  whole  field  of  photography,  as 
well  as  many  researches  upon  chemical 
actions  induced  or  hastened  by  light,  encour- 
ages the  researchers  who  have  already  started 
on  this  quest.  It  has  been  claimed  by  one 
observer  (Bach),  that  an  organic  compound 
termed  formaldehyde,  usually  regarded  by 
botanists  as  the  first  step  in  the  synthesis  of 
sugars  by  the  green  plant,  is  formed  artificially 
when  in  the  presence  of  sunlight,  carbon- 
dioxide  is  passed  through  a  solution  of  a  salt 
of  uranium.  Traces  of  this  organic  body  are 
also  stated  by  Fenton  to  be  produced  when 
metallic  magnesium  is  immersed  in  water 
that  has  been  saturated  with  carbon-dit 
oxide. 


184    ORIGIN  AND  NATURE  OF  LIFE 

Much  patient  work  may  be  required  before 
the  exact  constituents  in  the  just  proportions 
are  experimentally  found  out,  as  well  as  the 
proper  conditions  of  temperature  and  exposure 
to  light  or  other  form  of  radiant  energy, 
to  produce  more  complex  organic  bodies,  but 
it  is  evident  that  we  are  here  face  to  face 
with  a  practical  experimental  problem,  and 
not  confronted  with  the  impossible,  or  doomed 
to  indulge  only  in  philosophical  speculation 
without  being  able  to  test  our  results. 

The  problem  we  are  attacking  now  is  that 
of  how  organic  matter  arose  endowed  with 
its  own  peculiar  energy-forms  in  a  world 
where  there  was  no  previous  trace — not  merely 
of  living  matter — but  of  dead  organic  matter. 
Such  a  lifeless  world  it  is  barely  possible  for 
us  as  inhabitants  of  this  green  earth  covered 
with  teeming  energetic  life  to  realizesor  pos- 
tulate to  ourselves. 

Yet,  in  this  lifeless  inorganic  world  some- 
where about  the  time  when  life,  on  account 
of  temperature  conditions,  first  became  pos- 
sible, living  creatures  promptly  (in  the  geo- 
logical sense)  became  present,  as  the  record 
of  the  older  sedimentary  rocks  teaches  us 
to-day. 

The  degree  of  chemical  complexity  capable 
of  existing  in  the  materials  found  on  the 


HOW   LIFE    CAME    TO    EARTH    185 

earth  is  definitely  and  sharply  fixed  by 
temperature.  At  a  white  heat  such  as  exists 
in  the  sun's  atmosphere,  we  have  seen  that 
only  elements  can  exist,  and  many  of  these 
are  decomposed  into  proto-elements.  At  a 
somewhat  lower  temperature  binary  com- 
pounds, such  as  the  oxides,  can  remain  in 
equilibrium,  in  incomplete  combination, 
becoming  more  and  more  complete  as  the 
temperature  falls,  and  as  soon  as  their  exist- 
ence becomes  possible  these  oxides  do  exist. 
Lower  still  in  the  scale  of  temperature, 
saline  compounds,  such  as  chlorides  of  the 
alkalies,  and  mutually  neutralized  acidic  and 
basic  oxides  combined  together,  can  stand 
the  heat.  Such  bodies  as  the  carbonates  of 
calcium  and  magnesium  can  now  be  present 
in  an  incomplete  state  of  combination, 
partially  as  oxide  and  partially  as  carbonate, 
in  labile  balance  as  the  temperature  fluctu- 
ates up  or  down,  and  the  pressure  of  carbon 
dioxide  in  the  atmosphere  changes.  When- 
ever the  environmental  conditions  make  their 
presence  possible,  these  more  complex  forms 
must  promptly  make  their  appearance  by 
chemical  law. 

But  it  is  only  at  a  very  much  lower  tempera- 
ture that  compounds  at  all  complicated  in 
chemical  structure  can  exist  in  equilibrium, 


186    ORIGIN  AND  NATURE  OF  LIFE 

and  for  those  compounds  of  many  hundreds 
of  atoms  which  are  characteristic  of  life,  the 
range  is  narrowly  limited. 

Thus,  all  the  life  of  the  planet  would  be 
destroyed  at  a  temperature  which  we  may 
place  for  absolutely  inclusive  purposes  at 
56°C.  At  about  ten  degrees  below  this 
temperature  all  birds  and  all  mammals  would 
cease  to  exist.  The  other  species  would 
have  perished  long  before,  the  vast  bulk 
perishing  at  25°  to  30°  C,  which  is  below 
human  blood  heat.  Even  those  highly  organ- 
ized ferments,  called  enzymes,  which,  when 
separated  from  the  living  cell  that  bore 
them,  still  bear  half-impressed  upon  them 
certain  living  properties — all  these  suffer 
rapid  deterioration  in  all  known  cases  at 
50°  C,  and  at  60°  to  70°  C.  they  are  rapidly 
destroyed. 

Since  sedimentary  rocks  would  begin  to  be 
deposited  soon  after  the  surface  temperature 
of  the  earth  had  fallen  below  the  temperature 
of  boiling  water,  viz.,  100°  C,  the  early 
appearance  of  fossil  remains  in  the  older 
sedimentary  rocks,  when  due  allowance  has 
been  made  for  the  geological  time  necessary 
for  the  earth's  surface  to  cool  from  boiling 
point  to  the  life-temperature,  demonstrates 
the  important  point  that  as  soon  as  tempera- 


HOW   LIFE    CAME    TO    EARTH    187 

ture  allowed  sufficient  complexity  of  chemical 
structure  for  life  to  be  borne  upon  the  earth, 
then  life  appeared. 

This  note  cannot  be  too  strongly  sounded 
that  as  matter  is  allowed  capacity  for  assuming 
complex  forms  those  complex  forms  appear. 
As  soon  as  oxides  can  be  there,  oxides  appear : 
when  temperature  admits  of  carbonates,  then 
carbonates  are  forthwith  formed.  These  are 
experiments  which  any  chemist  can  to-day 
repeat  in  a  crucible.  And  on  a  cooling  planet, 
as  soon  as  temperature  will  admit  the  presence 
of  life,  then  life  appears  as  the  evidence 
of  geology  shows  us.  But  the  latter  cannot 
as  yet  be  repeated  by  the  chemist  because  the 
conditions  of  chemical  complexity  are  too 
delicate,  and  the  colloids  begin  to  show  their 
characteristic  slowness  of  reaction  and  delicacy 
of  balance. 

Next  in  order  of  development  prior  to  life, 
inorganic  colloids  begin  to  appear  in  solution, 
or  suspension,  in  the  waters  of  the  cooling 
globe,  alumina  and  silica  deposited  in  colloidal 
form  are  seen  in  many  sedimentary  rocks. 
Single  molecules  existing  in  solution,  and 
.capable  of  forming  colloids,  with  alterations 
in  temperature,  and  in  chemical  reaction  of 
the  environment,  begin  to  form  complexes, 
or  solution  aggregates,  in  which  the  unit  of 


188    ORIGIN  AND  NATURE  OF  LIFE 

chemical  structure  passes  from  the  atom  to 
the  molecule. 

Accompanying  these  structural  changes, 
the  energy  types  airfd  phases  inhabiting  the 
unit  of  structure  also  vary.  The  rates  of 
vibration  or  of  phasic  activity  in  the  colloidal 
aggregates  become  slower  than  in  the  simpler 
molecules  of  the  crystalloids.  All  that  has 
been  described  in  the  previous  chapter  as 
characteristic  of  colloids,  viz.,  slowness  of 
reaction,  meta-stable  equilibrium,  delicacy 
of  union,  and  increased  reactivity  of  specific 
type,  becomes  present  in  the  forms  of  matter 
now  capable  of  existing  in  equilibrium  with 
the  environment.  As  the  complexity  of 
structure  increases,  the  nature  of  the  equili- 
brium in  the  colloidal  aggregates  approaches 
more  and  more  towards  that  labile,  easily 
destroyed,  but  also  more  readily  constructive 
condition  which  has  been  described  as  charac- 
teristic of  life. 

It  may  then  be  summed  up  as  a  general 
law  universal  in  its  application  to  all  matter, 
although  varying  in  intensity  in  different 
types  of  matter,  and  holding  throughout  all 
space  as  generally  as  the  law  of  gravitation — 
a  law  which  might  be  called  the  Law  of  Com- 
plexity— that  matter  so  far  as  its  energy 
environment  will  permit  tends  to  assume  more 


HOW   LIFE    CAME    TO   EARTH    189 

and  more  complex  forms  in  labile  equilibrium. 
Atoms,  molecules,  colloids,  and  living  organ- 
isms, arise  as  the  result  of  the  operations  of  this 
law,  and  in  the  higher  regions  of  complexity 
it  induces  organic  evolution  and  all  the  many 
thousands  of  living  forms.  At  still  higher 
levels,  it  forms  the  basis  of  social  evolution 
and  leads  to  that  intellectual  development  in 
individual  and  community  which  surmounts 
the  whole  and  is  ever  building  upwards. 

In  this  manner  we  can  conceive  that  the 
hiatus  between  non-living  and  living  things 
can  be  bridged  over,  and  there  awakens  in 
our  minds  the  conception  of  a  kind  of  spon- 
taneous generation  of  a  different  order  from 
the  old.  The  territory  of  this  spontaneous 
production  of  life  lies  not  at  the  level  of 
bacteria,  or  animalculae,  springing  forth  into 
life  in  dead  organic  matter,  but  at  a  level  of 
life  lying  deeper  than  anything  the  microscope 
can  reveal,  and  possessing  a  lower  unit  than 
the  living  cell,  as  we  form  our  concept  of  it 
from  the  tissues  of  higher  animals  and  plants. 

In  the  future,  the  stage  at  which  colloids 
begin  to  be  able  to  deal  with  external  energy 
forms,  such  as  light,  and  build  up  in  chemical 
complexity,  will  yield  a  new  unit  of  life 
opening  a  vista  of  possibilities  as  magnificent 
as  that  which  the  establishment  of  the  cell 


190    ORIGIN  AND  NATURE  OF  LIFE 

as  a  unit  gave,  with  the  development  of  the 
microscope,  about  a  century  ago. 

It  was  no  fortuitous  combination  of  chances, 
and  no  cosmic  dust,  which  brought  life  to  the 
womb  of  our  ancient  mother  earth  in  the  far 
distant  Palaeozoic  ages,  but  a  well-regulated 
orderly  development,  which  comes  to  every 
mother  earth  in  the  Universe  in  the  maturity 
of  her  creation  when  the  conditions  arrive 
within  the  suitable  limits. 

Given  the  presence  of  matter  and  energy 
ty  forms  under  the  proper  conditions,  life  must 
come  inevitably,  just  as,  given  the  proper 
conditions  of  energy  and  complexity  of  matter 
in  the  fertilized  ovum,  one  change  after 
another  must  introduce  itself  and  give  place 
to  another,  and  spin  along  in  kaleidoscopic 
sequence  till  the  mature  embryo  appears, 
and  this  in  turn  must  pass  through  the  phases 
of  growth,  maturity,  reproduction,  decay, 
and  death. 

If  this  view  be  the  true  one,  there  must 
exist  a  whole  world  of  living  creatures  which 
the  microscope  has  never  shown  us  leading 
up  to  the  bacteria  and  the  protozoa.  The 
brink  of  life  lies  not  at  the  production  of 
protozoa  and  bacteria,  which  are  highly 
developed  inhabitants  of  our  world,  but 
away  down  amongst  the  colloids,   and  the 


HOW   LIFE    CAME   TO   EARTH    101 

beginning  of  life  was  not  a  fortuitous  event 
occurring  millions  of  years  ago  and  never 
again  repeated,  but  one  which  in  its  primordial 
stages  keeps  on  repeating  itself  all  the  time 
and  in  our  generation.  So  that,  if  all  intelligent 
creatures  were  by  some  holocaust  destroyed, 
up  out  of  the  depths  in  process  of  millions 
of  years  intelligent  beings  would  once  more 
emerge. 

In  this  process  of  chemical  evolution  up 
to  the  stage  which  we  at  the  present  day 
regard  as  living,  it  is  to  be  observed  that  as 
the  non-living  colloid  becomes  more  and 
more  complex  and  accordingly  more  and  more 
labile,  it  at  the  same  time  must  become 
more  and  more  susceptible  to  the  influence 
of  external  stimulation  by  different  forms  of 
energy. 

This  means  that  it  must,  under  such 
conditions  that  it  can  remain  in  equilibrium 
without  decomposition,  become  more  and 
more  a  machine  for  uptake  and  utilization  of 
energy.  The  fact  that  the  present  basis  of 
the  system  of  living  creatures  in  the  world 
is  light  energy,  leads  to  the  view  that  at  a 
certain  stage  in  the  development  of  colloids, 
probably  long  before  the  appearance  of 
chlorophyll,  the  colloids  began  to  be  affected 
by  the  light,  and  acquired  the  property  of 


192    ORIGIN  AND  NATURE  OF  LIFE 

retaining  and  utilizing  light  energy  for  the 
further  development  of  structure,  or,  in  other 
words,  synthesis  of  more  complex  colloids. 

A  second  point  of  importance  is  the  gradual 
increase  in  time  periods  arising  as  development 
progressed.  The  simpler  a  chemical  reaction 
is,  as  a  general  rule,  the  more  instantaneous 
it  is  ;  with  increasing  complexity,  the  time 
phases  grow  longer. 

The  early  stages  in  development  up  towards 
life  would  hence  be  rushed  through  rapidly, 
and  be  easily  and  constantly  reproducible. 
As  complexity  increased  so  would  the  time 
grow  longer  for  any  chemical  evolution. 
More  especially  the  time  necessary  to  reach  any 
higher  stage  of  organization  de  novo  would 
be  immensely  increased  on  account  of  instab- 
ility and  tendency  to  break  down  again,  as 
different  and  more  delicately  balanced  stages 
were  passed.  There  would  here  come  in  the 
tendency  of  external  conditions  to  stop  the 
process  at  certain  levels,  and  the  steeper  slopes 
of  development  would  only  be  infrequently 
ascended,  until  the  establishment  of  something 
resembling  a  species,  but  still  short  of  life 
arose  by  a  run  over  into  a  stable  condition 
in  one  case  out  of  many  millions.  This 
species  of  highly  organized  colloid  could  then 
more  easily  sustain  and  reproduce  itself  by 


HOW   LIFE   CAME   TO   EARTH    193 

inoculation  into  suitable  material,  and  growth 
there,  than  by  starting  afresh  from  simpler 
bodies.  It  would  form  a  fixed  starting  point 
for  further  development,  just  as  at  the  stage 
of  living  things  each  new  species  would  form 
a  fresh  point  of  departure.  A  labile  equili- 
brium, stable  and  capable  of  reproducing 
itself  with  suitable  conditions  of  material 
and  environment  of  energy,  would  so  be  set 
up,  but  requiring  a  long  period  of  time  for 
re-development  if  once  the  type  were  lost. 

The  only  observer  who  has  claimed  to  have 
obtained  experimentally  the  evolution  of 
living  organisms  from  inorganic  sources  is 
Dr.  Charlton  Bastian,  who  was  earlier  an 
opponent  of  the  views  of  Pasteur,  and  a 
controversialist  with  Huxley  in  regard  to 
spontaneous  evolution.  Bastian  claims  that 
when  either  of  two  mixtures  of  inorganic 
constituents,  which  he  describes  in  detail, 
is  sterilized  at  a  temperature  of  110°  to  115°  C, 
in  a  hermetically  sealed  tube,  and  then  allowed 
to  remain  for  a  considerable  period  of  time, 
varying  from  three  to  six  months,  micro- 
organisms of  many  types  appear  which  were 
not  originally  present,  such  as  micro-cocci 
torulae,  vibriones,  and  moulds.  The  solutions 
used  were  as  follows  : — (a)  sodium  silicate, 
ammonium  phosphate,  dilute  phosphoric  acid, 


194    ORIGIN  AND  NATURE  OF  LIFE 

in  distilled  water,  and  (b)  sodium  silicate 
and  per-nitrate  of  iron,  also  in  distilled  water. 
The  latter  solution  gave  more  abundant 
organisms  according  to  the  author.  The 
exact  concentrations  used  may  be  found  in 
his  work  as  quoted  in  the  bibliography  at 
the  end  of  the  volume. 

No  results  are  said  to  be  obtained  in  a  short 
interval  such  as  one  or  two  weeks,  and  this 
is  used  as  evidence  to  prove  that  the  results 
found  in  other  tubes  kept  longer  are  genuine 
and  not  fortuitous  from  occasional  infection. 
The  proofs  relied  upon  by  Bastian  in  favour 
of  the  products  he  obtains  being  really  living 
organisms,  are  (1)  the  microscopic  appearances, 
(2)  the  staining  properties  to  micro-chemical 
reagents,  and  (3)  the  fact  that,  when  the 
structures  are  sown  into  proper  nutrient 
materials,  then  they  reproduce  themselves 
just  as  micro-organisms  would  reproduce 
themselves  when  sown  into  a  nutrient  medium. 
Bastian  draws  a  careful  and  quite  legitimate 
distinction  between  a  nutrient  medium  con- 
taining material  capable  of  nourishing  and 
causing  to  multiply  a  micro-organism  already 
there,  and  a  medium  capable  of  causing 
organisms  to  engender. 

An  important  point  is  that  Bastian  found 
that    generation    occurred    better    and    the 


HOW    LIFE    CAME    TO    EARTH    195 

organisms  were  more  plentiful  when  the 
sealed  tubes  were  exposed  during  these 
months  to  diffuse  daylight.  This  appears 
to  have  been  an  incidental  experience,  but 
if  these  results  of  Bastian  are  real,  it  is  obvious 
that  some  such  form  of  energy  must  be  made 
available  in  order  that  organic  may  arise  from 
inorganic  matter.  Some  batches  of  tubes 
were  indeed  found  to  engender  more  imper- 
fectly in  an  incubator,  but  this  incubator  was 
heated  by  an  incandescent  electric  light 
placed  within  it  so  that  a  source  of  radiant 
energy  was  available  here  also. 

It  is  also  to  be  noted  that  the  composition 
of  the  two  fluids  for  which  success  is  claimed, 
happens  to  be  just  that  which  will  throw  the 
silicic  acid,  or  mixture  of  silicic  acid  and 
ferric  oxide,  into  the  condition  of  a  labile 
colloid  most  favourable  for  energy  capture. 

In  the  first  solution  mentioned  above,  the 
sodium  silicate  on  account  of  its  alkalinity  is 
non-colloidal,  but  to  this  is  added  a  small 
amount  of  phosphoric  acid  in  presence  of  a 
small  amount  of  ammonium  phosphate.  This 
addition  will  just  give  that  faint  acidity  which 
will  make  the  colloidal  silicic  acid  appear, 
without,  on  the  other  hand,  being  so  acid  as 
to  throw  the  colloid  out  of  solution.  In  the 
case  of  the  second  solution,  the  ferric  ni: 


196    ORIGIN  AND  NATURE  OF  LIFE 

solution  is  acid,  and  when  this  is  added  to  the 
alkaline  sodium  silicate,  the  tendency  is  to 
form  a  mixture  of  two  colloids,  viz.,  colloidal 
silicic  acid,  and  colloidal  ferric  hydrate. 
From  this  point  of  view  it  is  of  interest  to 
note  that  the  optimal  condition  at  which 
the  experimenter  is  instructed  to  aim  by 
Bastian,  is  that  at  which  a  small  amount  of 
precipitate  appears  some  time  after  sterilizing. 
This  empirical  direction  simply  means,  to  the 
chemist,  that  the  point  is  to  be  aimed  at 
where  colloid  is  formed  but  not  precipitated. 

These  experiments  as  to  evolution  of  organ- 
isms from  inorganic  solutions  have  not  been 
repeated  by  other  observers  but  such  test 
experiments  and  others  upon  similar  lines,  are 
now  in  progress. 

The  conditions  in  these  later  experiments 
of  Bastian  are  essentially  different  from  those 
of  his  earlier  work,  a  fact  which  does  not 
appear  to  have  been  fully  realized  by  those 
who  have  adversely  criticized  them  without 
attempting  their  repetition. 

There  is  one  thought  which  occurs  to  the 
mind,  and  that  is,  that  what  might  have 
been  expected  would  have  been  simple 
organic  bodies  in  solution  rather  than  micro- 
organisms. In  science  the  unexpected  has, 
however,    a  remarkable   way   of   happening, 


THE    LIVING    ORGANISM        197 

and  it  may  be  found  that  within  a  period  of 
three  to  six  months,  in  presence  of  suitable 
energy  sources  and  a  suitable  transformer 
of  colloidal  character  for  transforming  such 
energy,  the  level  of  micro-organisms  may 
possibly  be  attainable. 


CHAPTER    IX 

THE   LIVING   ORGANISM   AT   WORK 

In  the  preceding  chapters  a  continuous 
process  of  evolution  has  been  traced  out  from 
the  electron  to  the  atom,  from  the  atom  to  the 
molecule,  from  the  molecule  to  the  colloid, 
and  so  to  the  confines  of  the  organic  world. 
In  the  territory  of  living  organisms,  the 
continuity  remains  unbroken  for  all  living 
creatures  are  made  up  of  structural  units. 
The  unit  of  the  biologist  is  the  living  cell. 
All  living  creatures  are  composed  of  one  or 
more  of  these  units,  called  living  cells,  and 
the  biologist  divides  his  realm  into  two 
great  divisions,  that  of  the  unicellular  or- 
ganisms (protozoa  and  protophytes),  and 
that  of  the  multicellular  organisms  (metazoa 
and  metaphytes). 


198    ORIGIN  AND  NATURE  OF  LIFE 

The  living  cell  consists  of  a  combination 
of  colloids  existing  in  dynamic  equilibrium 
with  one  another,  and  carrying  on  an  exchange 
of  energy  phenomena  peculiar  to  living 
matter  with  one  another  and  with  their 
environment.  The  study  of  these  energy 
changes  forms  the  province  of  the  physiologist 
and  bio-chemist. 

The  character  of  the  energy  reactions  varies 
in  a  very  specific  way  from  one  type  of 
cell  to  another,  dependently  upon  minute 
and  delicate  differences  in  colloidal  structure 
in  the  different  kinds  of  cell.  It  has  been 
seen  that  as  structure  became  more  complex, 
energy  exchanges  also  varied,  and  it  is 
accordingly  only  to  be  expected  that  the  acme 
of  this  differentiation  should  occur  at  the 
most  complex  range  of  all  in  the  living  cells 
of  higher  animals.  It  is  upon  this  that  the 
vast  number  of  varieties  of  living  types 
depends,  and  here  arises  that  individuality 
and  fine  differentiation  which  is  found  in 
higher  animals  and  in  man. 

The  body  of  one  of  the  higher  animals, 
or  man,  consists  of  an  enormous  assemblage, 
or  community,  of  many  millions  of  millions 
of  such  living  units  far  outnumbering  the 
total  population  of  human  individuals  on  the 
earth,  and  this  vast  community  of  living  cells 


THE    LIVING    ORGANISM        199 

which  together  constitute  a  living  man  or 
woman,  are,  in  a  state  of  health,  so  co-ordin- 
ated and  regulated  as  to  excel,  in  goodness 
of  government  and  co-adaptation  to  one 
another's  wants,  any  social  system  which  has 
ever  regulated  a  body  corporate  in  human 
history.  There  is  just  as  much  division  of 
labour  and  mutual  assistance  and  governance 
as  in  a  state  or  vast  empire,  and,  moreover, 
there  are  scarcely  any  of  the  defects  of  a  bad 
government  in  the  affairs  of  men  in  a  social 
community,  which  may  not  find  their  parallel 
in  the  organic  happenings  in  a  single  human 
body  when  invaded  by  disease.  Similar 
types  of  cell  are  aggregated  together  into 
formations,  called  tissues,  designed  for  serving 
some  common  office  of  the  body,  and  at 
times  two  or  three  tissues  are  blended  together 
to  form  what  is  termed  an  organ  for  carrying 
out  some  special  task.  The  stomach  may 
be  taken  as  an  example  of  such  an  organ. 
Internally  it  possesses  a  layer  in  which  are 
millions  of  cells  formed  into  little  tube-like 
glands,  which  secrete  a  digestive  fluid  and 
pour  it  out  by  millions  of  minute  ducts  or 
pores  upon  the  food  contained  in  the  cavity 
of  the  stomach.  Outside  this  glandular 
layer  there  is  a  series  of  layers  of  contractile 
substance  called  muscle,  beautifully  designed 


200   ORIGIN  AND  NATURE  OF  LIFE 

and  arranged,  and  the  degree  of  contraction 
of  the  constituent  cells  of  this  muscular  layer 
enables  the  stomach  to  adapt  itself  to  the 
amount  of  food  within,  and  keep  up  a  certain 
pressure  upon  its  contents.  As  the  stomach 
expands  when  food  enters,  the  walls  become 
thinner  by  the  elongation  of  the  muscular 
cells,  and  as  the  food  is  passed  onwards  towards 
the  intestine  the  muscle  cells  shorten  again, 
so  as  always  to  keep  the  stomach  full  at 
different  sizes.  Thus  a  cavity  is  obtained 
with  an  adaptation  to  the  amount  of  its 
contents,  much  more  perfect  than  would  be 
given  by  a  rubber  bag  which,  of  inanimate 
receptacles,  more  nearly  resembles  it  than 
any  other.  In  addition  to  this  steady  tone 
of  the  stomach  walls,  increased  contractions 
occur  in  regular  series  with  a  slow  rhythm, 
and  these  serve  the  purpose  of  mixing  up  the 
food  and  the  digestive  secretion.  Further, 
when  digestion  has  proceeded  far  enough, 
and  the  condition  of  the  contents  of  the 
intestine  warrant  it,  these  movements  serve 
the  purpose  of  passing  the  food  onwards 
into  the  lower  part  of  the  alimentary  tube. 
Similar  instances  of  adaptation  of  structure 
and  function  might  be  multiplied  by  the 
thousand  all  over  the  body.  Such  delicate 
adaptation,  which  in  some  cases  is  demon- 


THE    LIVING    ORGANISM        201 

strable  to  the  unaided  eye,  and  in  other  cases 
only  when  the  aid  of  the  microscope  is 
invoked,  passes  even  beyond  visible  structure, 
onward  into  the  region  of  chemical  structure, 
for  it  is  found  that  nearly  every  tissue  (or 
assemblage  of  similar  cells)  of  the  body 
secretes  certain  chemical  substances  into  the 
general  blood  stream  which  are  carried  around 
to  another  situation  in  the  body  where  there 
is  a  different  assemblage  of  another  kind  of 
cell  to  be  benefited  by  this  internal  secretion, 
as  it  is  called.  So  close  is  this  chemical 
sympathy,  and  so  absolutely  necessary  are 
the  chemical  substances  so  formed,  which 
have  been  called  hormones,  or  excitants,  that 
the  loss  of  one  of  them  in  many  well-known 
instances  leads  to  such  changes  that  the 
death  of  the  whole  animal  results. 

This  kind  of  biological  civilization,  or 
social  economy,  within  the  whole  animal, 
and  the  interdependence  of  all  parts  upon 
a  wide  commerce  of  exchange,  is  the  most 
fundamental  thing  in  the  physiology  of  the 
higher  animal.  Apart  from  gross  lesions 
due  to  injury,  it  may  be  said  that  all  the 
problems  of  disease,  and  all  the  causes  of 
death,  depend  upon  the  upset  of  the  delicate 
balance  of  such  chemical  exchanges  between 
the  various  types  of  cells  composing  the  body. 


202    ORIGIN  AND  NATURE  OF  LIFE 

The  mischief  may  arise  in  two  fundamental 
ways,  (1)  perversion  of  the  functions  of  some 
assemblage  of  cells  from  within  so  that 
the  chemical  products  yielded  are  different, 
and  so  become  poisonous  to  these  or  some 
other  set  of  cells  ;  or  (2)  invasion  by  disease 
organisms  or  parasites  which  multiply  and 
produce  foreign  chemical  substances.  These 
poisonous  substances  irritate  and  finally  kill 
the  normal  cells,  either  locally  where  they 
are  situated,  or  by  discharge  of  soluble 
chemical  poisons  into  the  blood  stream, 
which  are  then  carried  away  all  over  the 
body  to  other  tissues,  and  incapacitate 
or  destroy  their  living  cells.  The  organisms 
of  disease  do  not  injure  or  kill  simply  by 
their  presence,  they  do  so  by  chemical  poisons 
which  play  in  upon  the  delicate  balance  of 
the  colloids  of  the  living  cells  of  the  body. 
The  degenerations  and  obvious  effects  of 
disease,  such  as  are  obvious  to  the  unaided 
eye  or  by  the  help  of  the  microscope,  are 
practically  all  produced  by  such  poisonous 
chemical  products. 

Both  in  their  outward  form  as  viewed  under 
the  microscope,  in  size,  and  in  grosser  internal 
structure,  as  well  as  in  specific  chemical 
structure,  living  cells  differ  enormously.  Thus, 
amongst    unicellular    organisms,     there    are 


THE   LIVING   ORGANISM        203 

exceedingly  minute  forms,  some  quite  harm- 
less and  even  beneficial,  and  others  the 
exciting  causes  of  more  than  half  the  ills 
that  flesh  is  heir  to.  These  tiny  organisms, 
sometimes  form  practically  structureless  col- 
loidal globules,  as  far  as  the  highest  resolving 
powers  of  the  microscope  reach,  which  are 
known  as  micro-cocci.  Yet  each  one  of  these 
minute  dots  forms  a  little  microcosm,  made 
up  in  each  species  of  micro-coccus  of  a 
highly  specific  grouping  of  complex  colloidal 
molecules,  with  a  commerce  of  chemical 
exchanges  entirely  its  own,  and  unlike  that 
of  any  of  the  other  species  of  micro-cocci.  So 
that  in  the  majority  of  cases  it  is  by  its 
effects  and  bio-chemical  reactions  alone  that 
a  micro-coccus  can  be  distinguished  from 
others  microscopically  indistinguishable  from 
it.  The  advance  of  modern  bacteriology  has 
made  it  absolutely  indispensable  to  the 
bacteriologist  to  possess  a  highly  special 
training  in  bio-chemistry,  and  micro-organisms 
are  nowadays  distinguished  far  more  by  the 
reactions  which  they  induce  in  culture  media, 
or  in  the  fluids  taken  from  man  or  another 
mammal,  or  by  the  specific  changes  which 
they  produce  in  the  body  as  a  whole,  than  by 
examination  with  the  microscope.  The  micro- 
scope, as  a  rule,  gives  the  bacteriologist  only 


204    ORIGIN  AND  NATURE  OF  LIFE 

a  first  rough  orientation  and  places  the 
organism  in  a  group  ;  its  identification  then 
follows  from  its  chemical  behaviour,  and  in 
all  chemistry  there  are  no  reactions  so  delicate 
and  specific  as  those  induced  by  these  minutest 
of  living  organisms. 

Two  micro-organisms  so  closely  similar  that 
a  skilled  bacteriologist  cannot  distinguish 
them  by  examination  with  the  highest  powers 
of  the  microscope,  when  they  invade  the 
body  of  man,  or  are  inoculated  into  an 
animal,  produce  two  diseases  absolutely 
specific  and  quite  different  from  each  other. 
The  physician  can  diagnose  the  two  diseases 
with  the  greatest  ease,  and  in  all  cases  of 
infection  the  one  germ  produces  its  own 
disease,  and  the  other  quite  as  definitely  its 
special  disease  with  definite  symptoms.  Each 
micro-organism  produces  its  own  specific  set 
of  chemical  poisons  called  toxins,  and  these 
toxins  have  special  affinities  for  certain  of 
the  tissue  cells,  on  account  of  adaptation  of 
structure  of  the  colloid  molecule  of  the  toxin 
to  the  colloids  of  the  cells  of  the  affected 
tissue.  In  fact,  these  two  fit  together  almost 
like  a  highly  complex  lock  and  key,  while 
other  colloids  of  other  tissue  cells  devoid  of 
such  specific  adaptation  are  left  entirely 
unaffected.     This  accounts  for  the  favourite 


THE    LIVING    ORGANISM        205 

sites  of  growth  of  different  micro-organisms 
in  the  body;  for  the  chemical  constitution 
of  one  kind  of  cell,  such  as  a  cell  in  the  intestine 
say,  suits  one  organism,  while  another  finds 
its  best  pabulum  in  the  lung,  another  in 
muscle,  and  another  in  the  cavity  of  a  joint. 
By  means  of  the  chemical  sympathy  above 
mentioned,  while  one  site  may  best  suit  the 
growth  of  an  organism,  quite  another  site 
and  type  of  cell  may  be  most  adapted  to 
react  with  its  poison,  or  toxin,  so  the  obvious 
and  dangerous  results  of  the  disease  may 
appear  at  points  remote  from  the  invading 
army.  Thus,  the  organism  responsible  for 
the  production  of  diphtheria,  for  example, 
grows  in  a  restricted  area  of  the  tonsils 
and  throat,  small  compared  with  the  bulk 
of  the  body.  Apart  from  occasional  diffi- 
culties of  a  mechanical  nature  connected 
with  respiration,  the  local  effects  are  not 
dangerous.  But  the  minute  organisms  produce 
a  soluble  chemical  substance,  the  diphtheria 
toxin,  which  is  of  the  same  order  of  deadliness 
as  snake  venom.  This  is  discharged  into 
the  blood  stream,  and  is  absorbed  chiefly 
by  two  types  of  body-cells,  on  account  of  the 
above-mentioned  chemical  adaptation  of  its 
molecule  to  their  particular  colloids.  These 
two  tissues  happen  to  be  master-tissues  of 


206   ORIGIN  AND  NATURE  OF  LIFE 

the  body,  the  work  of  which  cannot  even 
temporarily  be  interfered  with,  namely,  the 
heart  muscle,  and  certain  important  nerve- 
centres  controlling  respiration  and  heart-beat. 
As  the  poison  from  the  diphtheria  organisms 
locks  into  the  labile  oscillating  colloid  aggre- 
gates of  these  rhythmically  working  cells, 
their  character  alters. 

It  is  as  if  a  strange  key  had  become  jammed 
in  a  beautifully  constructed  lock,  so  that  its 
own  key  could  no  longer  shoot  the  bolt  of  the 
lock  to  and  fro.  When  the  amount  of  poison 
absorbed  passes  a  certain  limit,  the  heart 
becomes  irregular  or  the  respiration  troubled, 
and  soon  there  too  often  happens  the  sudden 
death  from  heart  collapse,  or,  if  that  be 
prevented,  the  serious  paralyses  of  other 
nerve  centres  seen  later  in  severe  cases  of  the 
disease. 

Strange  to  say,  it  is  just  the  violently 
poisonous  nature  of  the  toxin  of  diphtheria 
which  has  enabled  modern  biological  science 
to  supply  a  remarkable  bio-chemical  specific 
for  its  treatment,  such  as  cannot  be  produced 
for  a  disease  with  a  toxin  of  low  poisonous 
power,  as,  for  example,  tuberculosis.  The 
procedure  illustrates  so  well  the  delicate 
relationships  and  balance  of  the  colloids  of 
cells,  and  the  natural  mode  of  limitation  of 


THE    LIVING    ORGANISM        207 

diseases,  that  a  brief  outline  of  it  may  prove 
interesting.  When  an  alien  organism  has 
invaded  an  animal  and  commenced  to  form 
poisons  from  the  nutrition  supplied  by  its 
host,  there  is  always  a  reaction  induced 
against  the  infection.  There  are  two  modes 
of  combat,  one  by  means  of  a  vast  number 
of  free-living  cells  in  the  blood-stream  of  the 
host,  which  engulf  and  digest  the  bodies  of 
the  attacking  organism.  In  so  digesting 
these  organisms,  these  disease-resisting  cells 
(called  leucocytes)  produce  substances  which 
have  the  exactly  opposite  effects  to  the 
toxins,  and  are  called  anti-bodies  or  antitoxins. 
Secondly,  other  cells  in  the  body,  while  they 
do  not  engulf  and  swallow  the  foreign  organism 
join  in  producing  anti-bodies,  which  weaken 
and  kill  the  invading  organisms,  and  also 
combine  with  and  neutralize  the  toxins  which 
the  organisms  have  produced,  and  by  saturat- 
ing these  prevent  them  attacking  the  tissue 
cells. 

It  is  such  a  struggle  as  this  which  sets  a 
date  to  the  duration  of  all  the  acute  infectious 
diseases,  and  the  more  poisonous  the  products 
of  the  invading  organism,  so  much  the 
sharper  and  shorter  the  struggle.  It  is  the 
production  of  the  anti-bodies  in  addition  to 
chemical  charges  induced  in  the  body  cells 


208    ORIGIN  AND  NATURE  OF  LIFE 

which  confer  the  more  or  less  perfect  after- 
immunity  from  any  second  attack  of  the 
disease.  As  a  rule,  the  more  acute  and 
poisonous  a  disease  product  the  greater  the 
after-immunity. 

On  this  knowledge  is  based  both  the 
anti-toxic  and  vaccine  treatments  of  disease 
so  successful  in  modern  days,  as  well  as 
many  of  the  new  methods  for  the  bacterio- 
logical diagnosis  of  disease  forms. 

In  the  antitoxic  treatment  of  disease, 
so  conspicuously  successful  in  diphtheria, 
a  vicarious  animal  is  called  in,  one  being 
chosen  which  is  itself  susceptible  to  the 
organism,  but  at  the  same  time  possesses  a 
fairly  high  resisting  power.  Such  an  animal 
in  the  case  of  diphtheria  is  found  in  the 
horse.  Next  the  organism  of  the  disease 
is  cultivated  on  a  fairly  large  scale  in  a 
nutrient  broth  or  fluid  culture  medium. 
After  some  days,  the  organisms  are  separated 
by  filtration  through  a  fine  filter  such  as  a 
Chamberland  or  Berkefeld  candle,  so  yielding 
a  fluid  in  which  the  toxins  of  the  disease  are 
dissolved.  This  filtrate  is  then  injected  in 
graduated  doses  into  the  vicarious  animal. 
The  cells  of  this  animal  set  up  a  reaction, 
destroy  the  poison,  and  manufacture,  in  ex- 
cess, anti-toxins.     The  process  is  continued 


THE    LIVING    ORGANISM        209 

until  the  fluid  part  of  the  blood  of  the 
animal  is  as  highly  charged  as  possible 
with  the  antitoxin,  and  the  animal  itself 
is  now  immune  to  the  disease.  Incidentally, 
it  may  be  mentioned  that  this  is  what  is 
achieved  in  the  body  of  man  himself  (or 
highly  valuable  animals)  by  preventive  vacci- 
nation or  inoculation,  as  in  smallpox  vaccina- 
tion. 

Now,  returning  to  antitoxic  treatment, 
small  quantities  of  the  blood  of  such  an 
immunized  animal  when  drawn  off  contain 
dissolved  in  the  fluid  part  of  the  blood  (or 
serum)  chemical  substances  capable  of  neu- 
tralizing the  poisonous  toxins,  and  these  are 
the  antitoxins,  or  natural  antidotes  to  the 
disease. 

Such  is  anti-diphtheritic  serum  or  diphtheria 
antitoxin.  It  produces  its  wonderful  effect 
by  yielding  early  in  the  disease  a  supply  of 
just  that  material  which  the  body  is  struggling 
to  make  for  itself,  and  this  auxiliary  supply 
both  protects  the  vulnerable  tissues,  and 
being  absorbed  by  the  invading  organisms, 
weakens  them  at  an  early  stage  when  as  yet 
they  are  not  very  abundant  and  so  renders 
them  both  less  productive  and  also  an  easier 
prey  to  the  natural  forces  at  work. 

It  is  now  readily  seen  why  the  anti-toxic 


210    ORIGIN  AND  NATURE  OF  LIFE 

treatment  is  more  adapted  for  dealing  with 
small  amounts  of  a  virulent  poison  than 
with  larger  amounts  of  a  weaker  poison, 
for  the  excess  of  vicarious  antidote  cannot 
be  raised  to  a  high  level.  Also  the  less 
virulent  poison  of  a  chronic  infectious  disease, 
such  as  tuberculosis,  does  not  by  a  violent 
reaction  of  the  body  lead  to  a  heavy  produc- 
tion of  anti-toxin,  and  the  anti-toxin  produced 
in  response  is  also  not  such  a  deadly  negative 
so  far  as  the  invading  disease  organism  is 
concerned. 

With  such  a  heavy  handicap  to  fight  against, 
it  is  obvious  that  tuberculin  treatment, 
which,  while  differing  in  detail,  is  conceived 
on  the  same  lines,  can  only  be  successful 
when  applied  very  early,  and  when  there  is 
no  very  massive  infection  to  contend  against. 
This  is  the  reason  why  it  has  found  more 
success  in  joint  cases  where  the  infection  is 
more  limited. 

Vaccine  treatment  differs  from  anti-toxic 
treatment  in  that  the  vicarious  animal  is 
dispensed  with,  and  a  culture  of  the  organisms 
of  the  disease,  made  if  possible  from  a  strain 
obtained  from  the  actual  patient,  is  first 
sterilized  and  then  injected.  Conspicuous 
success  has  followed  the  vaccine  treatment 
in  certain  chronically  recurring  skin  affections, 


THE   LIVING   ORGANISM        211 

such  as  acne,  and  feruncle  (or  boils),  more 
especially  when  cultures  have  been  carefully 
made  from  the  strain  of  organism  in  the 
patient's  own  body  which  is  actually  causing 
the  disease.  This  has  now  become  a  standard 
treatment  in  such  diseases. 

In  diagnosis  also  these  chemical  reactions 
have  yielded  great  aid  to  practical  medicine, 
and  to  us  here  these  diagnostic  reactions  are 
of  high  interest  because  of  the  beautiful 
examples  they  provide  of  the  delicate  struc- 
tures and  reactions  which  have  become 
evolved  as  a  result  of  the  increasing  com- 
plexity of  design  in  living  organisms.  One 
example  must  suffice  as  a  sample  of  the 
whole.  A  certain  percentage  of  cases  of 
enteric  fever  are  very  difficult  to  diagnose 
on  account  of  absence  or  variation  of  import- 
ant clinical  symptoms  characteristic  of  typical 
cases  ;  but  a  very  simple  bio-chemical  test 
here  furnishes  a  valuable  indication.  Enteric 
fever  is  caused  by  a  motile  microscopic  bacillus 
(the  Bacillus  typhosus),  which  moves  about 
by  means  of  long,  fine,  whip-like  processes  at 
one  end  of  a  short  stout,  rod-like  body.  This 
organism  can  readily  be  cultivated  artificially 
in  nutrient  broth  and  other  artificial  media, 
and  when  a  drop  of  this  nutrient  fluid,  diluted 
with  a  dilute  solution  of  salt  of  the  proper 


212    ORIGIN  AND  NATURE  OF  LIFE 

strength,  is  placed  under  a  microscope, 
the  organisms  are  to  be  seen  propelling 
themselves  about  actively  in  all  directions, 
and  fairly  uniformly  distributed.  The  same 
effect  is  seen  if  the  enteric  culture  be  mixed 
with  a  small  amount  of  the  fluid  part  of  the 
blood  of  a  normal  person  (diluted  normal 
serum).  But  if  the  serum  of  a  person  suffering 
from  enteric  fever  be  taken,  a  minute  drop 
being  all  that  is  necessary,  and  equally 
diluted,  then  on  mixing  this  with  the  enteric 
culture  as  before,  and  examining  under 
the  microscope  a  most  remarkable  result  is 
seen.  All  the  enteric  organisms,  which  before 
were  swimming  about  freely,  in  about  ten 
to  fifteen  minutes  are  found  to  have  gathered 
themselves  together,  into  clumps  of  half-a- 
dozen  to  a  score,  or,  as  it  is  termed,  have 
agglutinated.  The  flagellae  are  still  moving 
but  only  to  preserve  the  clumped  arrange- 
ments. If  bacteria  possessed  minds  it  would 
almost  seem  as  if  the  situation  were  being 
debated  at  meetings,  much  as  war  news 
might  be  discussed  in  a  distracted  com- 
munity. The  chemical  basis  of  the  pheno- 
menon is  that  in  the  blood  of  the  patient 
afflicted  with  the  enteric  fever,  minute  traces 
of  an  anti-body  to  the  enteric  organism  have 
been  produced  in  an  amount  far  too  slight 


THE   LIVING   ORGANISM        213 

to   demonstrate   by   any   ordinary   chemical 
reaction  known  to  us,  but  easily  demonstrable 
by    this    bio-chemical    test.     This    inimical 
substance  has  been  suddenly  presented  to  the 
enteric  organisms  cultivated  artificially  out- 
side,   and    this   agglutination   is   the   result. 
The  agglutination  is  probably  due  to  altera- 
tions in  what  is  called  surface  tension  at  the 
interface  between  the  organism  and  the  fluid 
in   which  it   is  immersed.     The  reaction   is 
so  delicate  and  specific  that  it  will  occur  even 
when  the  enteric  serum  is  diluted  two-hundred- 
fold in  a  typical  case.     First  discovered  for 
the  enteric  organism,  this  property  of  agglu- 
tination has  since    been  extended  to  many 
others,  and  is  now  used  as  a  routine  method 
of  settling  the  identity  of  suspected  organisms, 
as  well  as  for  diagnosing  the  nature  of  indivi- 
dual cases  of  disease.     Nearly  allied  organisms 
cause    mutual    agglutination,    each    for    the 
other,   in  fluids   in  which  cultivations  have 
been    previously    made,    and   the    degree    of 
dilution  at  which  agglutination  occurs  indi- 
cates   the    closeness    of     relationship    in    a 
group,  or  complete  identity.    Organisms  more 
remote    have   no   effect   upon    one   another. 
It  is  thus  seen,  even  at  the  level  of  bacteria, 
how  complex  and  finely  balanced  the  structure 
of  the  colloids  has  become.   It  will  presently 


214   ORIGIN  AND  NATURE  OF  LIFE 

be  shown  how  these  balanced  relationships 
and  sympathetic  chemical  affinities  of  colloids 
become  intensified  and  individualized  as  the 
complex  cell  colonies  come  into  co-existence 
in  the  same  organic  whole,  or  body  of  the 
higher  animal. 

It  must  not  be  supposed  that  all  bacteria 
exist  only  as  parasites  within  the  bodies  of 
man  and  the  higher  animals  ;  many  perform 
indispensable  functions  in  restoring  dead 
organic  matter  back  to  inorganic  forms, 
others,  more  directly  useful  still,  attach 
themselves  to  the  growing  rootlets  of  the 
plants  which  supply  our  food,  and  enable 
these  to  take  up  nitrogenous  nutrient  matter 
from  the  soil.  Without  such  common  life 
or  commensal  existence,  the  growth  of  some 
of  our  most  valuable  food  plants  would  be 
impossible. 

In  the  bacteria,  there  are  large  groups 
distinguished  by  the  form  of  the  organism, 
such  as  the  rounded  micro-cocci,  which  are 
subdivided  again  according  to  whether  they 
grow  singly,  or  in  chains,  or  groups,  into 
mono-cocci,  diplo-cocci,  strepto-cocci,  and 
staphylo-cocci.  Similarly,  in  the  rod-like 
forms  of  bacteria  called  bacilli,  in  which 
the  relative  length  and  breadth,  straightness 
or  curvature,  presence  or  absence  of  motile 


THE    LIVING    ORGANISM        215 

structures,  staining  reactions,  and  bio-chemical 
reactions,  again  give  many  divisions,  which 
need  not  here  be  named. 

The  micro-organisms  hitherto  dealt  with  are 
all  usually  referred  to  a  subdivision  of  the 
fungi  amongst  the  plants  (Schizomycetes). 
There  are  in  addition  to  these,  many  thousands 
of  types  of  botanical  micro-organisms  belong- 
ing to  other  families,  some  parasitical,  and 
others  chlorophyllaceous,  and  building  up  their 
own  organic  materials. 

There  are  also  many  thousands  of  types 
well  known,  in  addition  to  many  as  yet 
unstudied  and  unclassified,  of  unicellular  or 
protozoan  animals,  found  chiefly  in  fresh  or 
marine  water,  in  the  fluids  of  soil,  in  higher 
plants  or  animals,  or  in  decaying  organic 
organisms  or  fluids. 

Many  of  these  protozoa  occurring  free  in  the 
blood  or  body-fluids  or  enclosed  in  the  living 
cells  of  plants  or  animals,  are  the  now  familiar 
causes  of  many  important  diseases.  Such 
animal  parasites,  unicellular,  and  of  micro- 
scopic dimensions,  seem  especially  to  take 
a  large  part  in  the  causation  of  tropical 
diseases,  such  as  malaria  and  sleeping  sick- 
ness. It  is  now  known  that  several  of  these 
protozoan  parasites  are  borne  from  one 
host  to  another  by  insects,   and   possess  a 


216    ORIGIN  AND  NATURE  OF  LIFE 

double  life-cycle,  in  part  consummated  in  man, 
and  in  part  in  the  insect. 

One  of  the  most  fatal  of  diseases,  syphilis, 
a  most  potent  factor  in  racial  degeneration, 
which,  unfortunately,  flourishes  in  all  climates, 
has  recently  been  shown  to  be  a  protozoan 
disease  carried  by  a  minute  animal  organism 
called,  from  its  spirally  arranged  or  twisted 
form,  a  spirochete. 

Most  classical  descriptions  of  a  typical 
living  cell  are  based  on  that  particular  class 
of  animal  cell  called  an  amoeboid  cell,  although 
the  word  cell  itself  is  derived  from  botany. 
In  plant  tissues  where  growth  is  fairly  rapid, 
the  cells  lie  close  alongside  of  one  another, 
separated  by  outer  membranes  or  cell  walls, 
so  that  the  appearance  comes  to  resemble  the 
cells  of  a  honeycomb. 

The  word  cell,  later  came  to  be  extended  to 
all  living  units  as  shown  by  the  microscope, 
although  the  wide  and  free  exchanges  of  cells 
with  one  another  make  the  word  rather  a 
misnomer,  and  the  typical  free  unicellular 
organism,  as  will  be  seen,  is  not  at  all  described 
by  the  word  in  its  usual  non-technical  meaning. 

Amoeboid  cells  are  found  in  sea  and  pond 
water  carrying  on  an  independent  existence, 
and,  in  a  dependent  form  as  to  nutriment, 
in  the  blood  and  body  fluid  of  higher  animals, 


THE   LIVING   ORGANISM        217 

where  some  of  their  useful  work  has  already 
been  mentioned.  An  amoeba,  as  a  parasite, 
is  also  responsible  for  a  form  of  disease  known 
as  tropical  dysentery. 

An  amoeboid  cell  is  a  microscopic  mass  of 
semifluid  consistency.  As  in  the  majority 
of  cases  of  living  cells,  about  three-fourths 
to  four-fifths  of  the  material  of  the  mass  is 
water,  and  in  this  water  are  contained  colloids, 
consisting  of  proteins,  fats,  carbohydrates 
and  other  bodies,  so  as  to  make  a  thin  mobile 
jelly-like  mass,  which  also  contains  certain 
crystalloids.  At  rest,  it  possesses  a  roughly 
globular  shape,  but  it  is  rarely  at  rest,  and  is 
more  usually  slowly  changing  its  shape  by 
means  of  slow  flowing  movements  called  out 
by  the  chemical  stimulus  of  nutrient  matter 
dissolved  in  the  fluid  in  which  it  is  floating. 
Such  dissolved  excitants  usually  emanate 
from  particles  suspended  in  the  fluid,  such 
as  debris,  or  bacteria,  and  if  any  such  particles 
near  to  an  amoeba  which  is  being  observed 
under  a  microscope  be  carefully  watched,  it 
will  often  be  noticed  that  the  amoeba  sends 
processes  out  towards  them,  and  finally 
flows  round  them  and  takes  them  into  its 
mass. 

This  does  not  always  happen,  the  determin- 
ing factor  is  whether  the  particle  possesses 


218    ORIGIN  AND  NATURE  OF  LIFE 

anything  of  nutrient  value  for  the  amoeba ; 
other  inert  particles,  as  a  rule,  are  left  alone. 

The  particle  after  being  engulfed  is  acted 
upon  and  digested  by  fluid  contained  in  the 
amoeba,  and  when  that  process  is  completed, 
any  particles  of  debris  which  have  accumulated 
are  got  rid  off  by  a  process  of  flowing  away 
from  them  which  is  the  exact  opposite  of  the 
process  of  uptake.  These  two  processes  of 
taking  in  and  giving  out  are  called  ingestion 
and  egestion.  They  can  occur  apparently 
at  any  part  of  the  microscopic  mass. 

Within  the  mass,  two  structures  may 
usually  be  made  out.  The  first  of  these  is 
not  a  universal  structure  in  cells,  and  is  called 
the  cell  vacuole  ;  it  seems  to  be  more  devoid 
of  structure  and  clearer  than  the  rest  as  if 
it  were  more  fluid.  It  slowly  varies  in  size 
from  time  to  time,  and  there  seem  to  be 
streaming  movements  about  it  as  if  it  were 
responsible  for  movements  of  fluid  and  a 
kind  of  circulation  of  dissolved  materials 
and  minute  suspensory  materials  within  the 
cell.  The  second  structure,  on  the  contrary, 
is  more  granular  and  solid-looking  than  the 
remainder.  It  is  only  dimly  seen  when  the 
cell  is  alive,  but  it  differs  in  chemical  nature 
from  the  rest  of  the  cell  contents,  as  is  shown 
by  the  fact  that  when  the  cell  is  killed  and 


THE   LIVING   ORGANISM        219 


Diagram  showing  the  Changes  in  the  Nucleus  when 
a  Cell  Divides  to  form  Two  Cells.  The  first 
sketch  shows  the  resting  condition  with  a  reticular 
nucleus,  the  next  shows  the  nucleus  matter  forming 
a  skein.  In  the  third  figure  the  skein  has  divided 
into  pieces  or  chromosomes,  the  fourth  figure  shows 
these  arranged  on  the  spindle  and  the  two  centres 
or  centrosomes.  In  the  fifth  figure  the  chromosomes 
are  splitting  lengthwise,  and  in  the  sixth  these  have 
travelled  to  the  two  poles.  The  remaining  figures 
show  the  inversion  changes  and  the  formation  of  the 
two  daughter  cells. 


220    ORIGIN  AND  NATURE  OF  LIFE 

treated  with  stains,  it  reacts  differently  from 
the  rest  with  these  chemical  substances. 
A  stain  which  unites  strongly  with  this  part 
usually  only  stains  the  other  parts  lightly 
or  not  at  all,  and  a  different  stain  may  behave 
in  exactly  the  reverse  manner.  This  view 
is  confirmed  when  many  other  different  types 
of  cell  than  the  amoeba  are  subjected  to 
chemical  examination.  Every  complete  and 
perfect  living  cell  possesses  one,  or  more, 
of  these  structures,  and  it  has  most  important 
relationships  to  the  processes  of  cell-reproduc- 
tion and  growth.  This  part  of  the  cell  is 
called  the  nucleus,  and  it  is  the  central  part 
of  the  whole.  When  a  cell  is  injured,  or 
mechanically  divided,  the  portion  attached 
to  the  nucleus,  even  if  it  be  the  smaller  part, 
usually  recovers  and  reproduces  a  whole  cell 
again,  but  a  part  containing  no  nucleus, 
or  portion  of  a  nucleus,  perishes  like  a 
branch  cut  off  from  a  tree.  Remarkable 
changes  in  the  nucleus  precede  the  processes 
of  reproduction  in  the  cell  when  one  cell  is 
about  to  form  two.  Before  reproduction 
commences,  the  nucleus  possesses  a  reticulate 
or  a  sponge-like  structure,  but  at  a  certain 
stage  in  the  cell-life,  some  chemical  alteration 
due  to  a  heaping  up  of  energy,  causes  this 
structure  to  alter  spontaneously.  The  peculiar 


THE   LIVING    ORGANISM        221 

material  of  the  nucleus  then  forms  itself 
into  a  thread-like  structure  so  as  to  look  like 
a  tangled  skein  of  thread,  which  later  shortens 
and  thickens.  Then  in  a  most  remarkable  way 
the  thread  divides  or  becomes  cut  up  into  a 
definite  number  of  short  lengths,  called 
chromosomes.  The  number  of  these  chromo- 
somes is  an  absolutely  fixed  and  always  an 
even  number  in  every  species  of  higher  animal 
or  plant.  In  man  there  are,  for  example, 
always  twenty-four  of  these  chromosomes 
formed.  The  chromosomes  were  formed  by 
equi-distant  cuts  across  the  skein,  but  now 
each  one  of  these  pieces  splits  lengthwise,  and, 
at  about  the  same  time,  two  attraction  points 
are  formed  some  distance  apart  in  the  cell, 
and  from  these  attraction  points  (or  centro- 
somes)  exceedingly  fine  gossamer-like  threads 
are  formed  radiating  from  the  centrosome, 
and  attached  along  the  length  of  each  split 
chromosome.  Along  these  fine  threads  the 
split  halves  of  the  chromosomes  part  company 
from  each  other,  and  travel  apart  from  each 
other,  until  finally  one  exact  half  of  the 
material  of  the  nucleus  in  the  form  of  split 
chromosomes  is  surrounding  each  centrosome. 
An  inverse  order  of  affairs  now  ensues  at 
each  of  these  daughter  nuclei,  whereby  first 
a  skein   and   then   a   reticulum   is   formed. 


222    ORIGIN  AND  NATURE  OF  LIFE 

Contemporary  with  these  latter  changes  in 
the  daughter  nuclei,  the  rest  of  the  colloid 
material  of  the  cell  begins  to  divide  simply 
around  the  two  daughter  nuclei,  indenting, 
becoming  hour-glass-shaped,  and  finally  divid- 
ing into  two  halves.  In  this  way  two  cells 
are  formed,  which  increase  in  size  until  once 
more  similar  energy  conditions  arise  and  lead 
to  a  fresh  division,  initiated  and  carried 
through  in  the  same  fashion. 

There  is  nowhere  outside  living  matter  a 
set  of  energy  phenomena  found  to  occur 
spontaneously  at  all  resembling  this  remark- 
able sequence  of  changes.  Diffusion  artefacts 
bearing  an  artificial  resemblance  have  been 
described,  but  these  do  not  occur  naturally, 
and  bear  no  real  analogy  to  the  living  pro- 
cesses. 

In  the  processes  of  cell-reproduction  and 
division  there  is  a  type  of  energy  at  work 
never  found  elsewhere  than  in  living  structures. 

There  is  one  interesting  exception  to  the 
process  of  nuclear-division  described  above, 
and  that  is  when  the  first  division  of  all  occurs 
in  the  maturation  of  the  ovum,  which  precedes 
the  sexual  production  of  a  new  individual  in 
the  higher  plant  or  animal.  An  early  stage 
in  the  history  of  the  new  individual  is  a 
union  of  two  cells  one  from  a  male  and  the 


THE   LIVING   ORGANISM        223 

other  from  a  female  parent.  If  the  fusion  of  the 
two  nuclei  took  place,  there  would  obviously  be 
at  each  generation  a  doubling  of  the  amount 
of  nuclear  matter  and  twice  the  normal  number 
of  chromosomes.  Nature  arranges  against 
this  by  a  remarkable  preparation  of  each 
parental  nucleus.  In  each  first  division  which 
occurs  in  each  parental  cell  before  the  male 
and  female  elements  come  in  contact,  only 
half  the  usual  number  of  chromosomes  is 
formed,  then  for  some  unknown  reason,  a 
re-arranging  division  occurs  with  the  usual 
number  of  chromosomes,  but  half  the  amount 
of  material  in  each  one.  At  each  of  these 
preparatory  divisions  in  the  female  cell,  one 
of  the  two  nuclei  formed  is  extruded  from  the 
cell  and  atrophies.  The  female  cell  does 
not  divide  as  a  whole  in  these  two  divisions  : 
only  its  nucleus  divides.  After  the  completion 
of  this  curious  process,  which  is  known  as 
maturation,  a  reduced  male  nucleus  and  the 
reduced  female  nucleus  unite  to  form  a 
first  mixed  nucleus  to  the  fertilized  ovum, 
in  which  the  two  sexes  obviously  share 
equally.  The  purpose  of  the  rejection  of  a 
part  of  each  nucleus  has  caused  much  dis- 
cussion, and  is  not  yet  at  all  clear,  but  it  is 
probably  closely  concerned  with  heredity 
and  species  preservation. 


224    ORIGIN  AND  NATURE  OF  LIFE 

This  is  another  fine  example  of  a  type  of 
energy  transformation  never  witnessed  any- 
where else  than  in  living  structures.  So  is 
also  the  long  series  of  co-ordinated  cell 
divisions  and  reproductions  in  the  growing 
embryo,  and  the  origin  in  unfailing  sequence 
from  one  cell  of  all  the  many  kinds  of  cell  and 
tissue  found  in  a  higher  plant  or  animal. 
The  fertilized  ovum  of  one  mammal  is  struc- 
turally indistinguishable  from  that  of  another, 
and  contains  in  it  nothing  representative  of 
the  many  diverse  structures  that  are  destined 
to  arise  in  course  of  development. 

But  the  colloids  possess  specific  differences, 
and  it  is  initially  inhabited  by  a  form  of  energy 
unknown  outside  life  processes,  which  leads 
the  mazy  dance  of  life  from  point  to  point, 
each  new  development  furnishing  a  starting 
point  for  the  next  one.  A  specific  colloidal 
structure,  with  a  definite  energy  distribution 
at  each  stage,  forms  the  opening  for  the 
next  stage.  It  has  been  seen  that  each 
structural  variation  in  matter  means  a 
different  energy  distribution,  and  to  deny 
that  the  energy  distributions  in  living  matter 
are  different  in  type  from  those  inhabiting 
inorganic  matter  would  be  as  absurd  as  to 
deny  that  different  energy  forms  exist  in  the 
inorganic  world,  each    characterized   by   its 


THE    LIVING    ORGANISM        225 

own  peculiar  set  of  phenomena.  No  energy 
exchanges  or  natural  phenomena  could  exist 
were  there  not  different  inorganic  types 
of  energy.  For  all  those  changes  which 
affect  our  senses  or  our  instruments  are 
due  to  energy  transformations  from  one 
energy  form  to  another.  The  words,  heat, 
light,  magnetism,  electricity,  and  those  terms 
designating  the  various  forms  of  radio- 
activity possess  a  meaning  although  all 
related  and  all  manifestations  of  physics 
and  chemistry.  Electrons,  atoms,  molecules, 
colloids,  cells  are  different  things,  though 
related  to  one  another.  The  chemical  elements 
must  be  recognised  as  existent — although 
transmutable.  Some  term  is  obviously 
required  applicable  to  the  entirely  peculiar 
set  of  energy  phenomena  witnessed  in 
living  matter,  such  as  bioiic  energy.  Heat 
energy  and  electrical  energy  are  mutually 
transmutable  one  into  the  other,  yet  it  is 
not  said  that  electrical  energy  is  heat  or  light 
because  these  appear  when  it  is  transformed. 
Why,  then,  should  a  form  of  energy  such  as 
inhabits  living  structures  be  thought  to  be 
only  a  mixture  of  heat  and  electricity  and 
chemical  energy,  because  these  are  obsen 
when  it  manifests  itself  ?  The  position  which 
denies   the   existence   of   a  form   of   energy 


226    ORIGIN  AND  NATURE  OF  LIFE 

characteristic  of  life  is  one  of  peculiar  absurdity 
even  for  the  pure  mechanician,  which  can 
only  be  explained  as  a  natural  reaction  from 
the  entirely  different  mediaeval  conception 
of  a  vital  force  which  worked  impossible 
miracles.  As  well  because  of  the  errors 
connected  with  the  idea  of  "  phlogiston " 
might  the  present  ideas  regarding  "  energy  " 
as  a  whole  be  scouted. 

It  is  biotic  energy  which  guides  the  develop- 
ment of  the  ovum,  which  regulates  the  ex- 
changes of  the  cell,  and  causes  such  phenomena 
as  nerve  impulse,  muscular  contraction,  and 
gland  secretion,  and  it  is  a  form  of  energy 
which  arises  in  colloidal  structures,  just  as 
magnetism  appears  in  iron,  or  radio-activity 
in  uranium  or  radium,  and  in  its  manifesta- 
tions it  undergoes  exchanges  with  other 
forms  of  energy,  in  the  same  manner  as  these 
do  amongst  one  another.  There  are  precisely 
the  same  criteria  for  its  existence  as  for  the 
existence  of  any  one  of  the  inorganic  energy 
types,  viz.,  a  set  of  discrete  phenomena;  and 
its  nature  is  as  mysterious  to  us  as  the  cause 
of  any  one  of  these  inorganic  forms  about 
which  also  we  know  so  little.  When  we  know 
why  hydrogen  and  oxygen  unite  to  form 
water,  then  we  shall  be  near  to  understanding 
the  balance  of  organic  colloids.     In  fact,  the 


THE    LIVING   ORGANISM        227 

knowledge  may  come  to  us  in  the  reverse 
order. 

With  the  development  of  the  ovum  of 
higher  plant  or  animal  into  its  myriad  brood 
of  different  types  of  cells  with  correspondingly 
different  functions,  the  last  great  stage  on  our 
journey  of  evolution  is  reached,  and  we  have 
now  to  consider  some  of  the  energy  phenomena 
which  arise  at  this  most  complex  stage  of  all, 
on  account  of  the  life,  or  energy  flux,  lived 
in  common  by  these  various  nations  of  cells. 

The  functions  served  by  many  of  the  great 
systems  of  tissues  of  the  body,  and  the 
co-relationships  of  these  to  one  another,  are 
so  obvious  as  to  require  only  passing  mention. 
There  is  the  jointed  osseous  system  of  bones, 
joints  and  ligaments  which  forms  the  skeleton, 
and  serves  the  purposes  of  preservation  of 
the  form  of  the  animal,  locomotion,  capture 
and  mastication  of  food,  and  the  performance 
of  skilled  manipulations  of  many  kinds. 
The  osseous  system  is  activated  by  the 
voluntary  muscular  system,  which  in  turn 
is  worked  by  the  immense  system  of  nerve 
cells  and  their  processes  (the  nerves)  connected 
with  brain  and  spinal  cord.  Each  apparently 
simple  voluntary  movement  such  as  those 
of  vision,  eating,  speaking  or  writing,  is  in 
reality,  as  shown  by  Sherrington's  researches, 


228    ORIGIN  AND  NATURE  OF  LIFE 

a  brilliantly  played  piece  of  biological  sym- 
phony by  hundreds  of  thousands  of  nerve  cells 
and  muscle  cells  playing  in  perfect  harmony, 
and  timed  sequence  of  performance.  Nutrition 
absolutely  adapted  in  quality  and  quantity 
must  be  provided  for  these  skilled  players, 
and  this  provides  work  for  the  great  digestive 
and  circulatory  systems,  which  also  are 
regulated  and  controlled  by  master  nerve- 
cells  both  of  the  central  nervous  system, 
and  of  a  special  nervous  system  of  their 
own  called  the  sympathetic  nervous  system. 
The  food  must  first  be  rendered  soluble  by 
digestive  ferments  manufactured  by  special 
glands,  and  poured  out  into  mouth,  or 
stomach,  or  intestine.  The  soluble  chemical 
products  must  be  built  up  upon  a  system 
for  which  each  type  of  animal  possesses  its 
own  plan  and  secret  device,  in  intestinal 
absorbing  cell,  in  liver,  and  in  lymph  gland, 
and  each  such  guild  or  craft  of  cells  knows 
its  own  cunning  workmanship,  The  speci- 
fically prepared  food  now  chemically  built 
up  to  the  exact  chemical  pattern,  in  whatso- 
ever protean  form  it  may  chance  to  have 
entered  the  mouth,  so  that  it  can  form  part 
of  the  circulating  blood,  is  borne  round  in 
endless  circuit  by  the  powerful  thrusts  of  the 
beating   heart.     By   the   branching   and   re- 


THE    LIVING    ORGANISM        229 

uniting  system  of  arteries,  capillaries,  and 
veins,  the  life-maintaining  fluid  is  diverted 
into  thousands  or  even  millions  of  capillary 
channels,  in  which  it  is  only  separated  from 
the  fluid  bathing  the  needy  tissues,  by  thin, 
transparent,  permeable  cells  compared  to  the 
thinness  of  which  the  finest  tissue  paper  is 
as  thick  as  hide.  Here  the  commerce  of 
chemical  exchange  goes  on  in  a  never-closing 
market.  Day  or  night,  asleep  or  awake, 
nutriment  is  taken  in  and  poisonous  excretory 
substances  given  out ;  but  also  all  types 
of  beautifully  manufactured  chemical  goods 
are  exchanged.  It  must  not  be  supposed 
that  nutriment  alone  is  taken  and  waste 
returned,  in  exchange  for  some  single  obvious 
service  to  the  community,  such  as  a  muscular 
contraction,  a  nervous  stimulus  given  at  the 
proper  instant  of  time,  or  the  elaboration  of 
a  digestive  secretion. 

The  classes  of  cells  are  greater  artists,  and 
take  wider  interests  than  this  ;  few  of  them 
resemble  in  narrowness  of  life  and  austerity 
of  outlook  the  so-called  human  specialist. 
In  nearly  every  case  the  cell  of  a  given  type 
possesses  what  might  perhaps  be  described 
as  a  hobby  in  addition  to  its  more  obvious 
function,  and  the  secret  hobby  is  often 
more  all-important  than  the  obvious  day's 


230    ORIGIN  AND  NATURE  OF  LIFE 

task-work,  for  in  some  instances  the  obvious 
function  may  be  destroyed  without  causing 
death,  its  place  being  undertaken  vicariously 
by  some  other  part,  but  interference  with  the 
hobby  usually  leads  to  sudden  and  remarkable 
death  of  the  whole  animal.  This  will  be 
reverted  to  later  when  the  other  main  systems 
have  been  mentioned. 

The  amount  of  blood  flowing  to  various 
parts  is  carefully  regulated  by  a  set  of  nerves, 
which  acting  upon  circularly  arranged  muscle- 
fibres  control  the  diameter,  or  calibre  of  the 
small  vessels  in  a  manner  much  more  perfect 
than  the  taps  on  a  town  water-supply.  Not 
only  must  food  be  borne  to  the  cells,  oxygen 
must  also  be  carried,  else  the  cells  could 
not  set  the  energy  of  the  food  free.  The 
waste  products  of  the  combustion  must  also 
be  carried  away.  This  office  is  accomplished 
by  the  respiratory  system,  which  carries  the 
gaseous  products  to  and  from  the  lungs  in 
solution  or  in  union  with  the  red  colouring 
pigment  of  the  blood  and  the  proteins,  while 
other  solid  waste  products  are  removed  in 
solution  by  the  renal  excretory  system. 

Excess  of  fluid  containing  waste  products, 
lying  between  the  tissue  cells  and  other 
constituents,  is  drained  off  by  a  system  of 
fine  vessels  called  the  lymphatics,  and  after 


THE    LIVING   ORGANISM        231 

undergoing  purification  in  structures  called 
lymphatic  glands,  is  returned  to  the  venous 
system  by  the  main  lympathic  ducts,  the 
whole  forming  the  lymphatic  system. 

Early  even  in  the  development  of  the 
embryo  animal,  and  long  before  birth,  those 
cells  in  male  or  female  which  are  to  serve  the 
purpose  of  carrying  on  the  tide  of  life  into 
the  next  generation,  by  uniting  with  cells 
from  an  individual  of  the  opposite  sex,  are 
segregated  off  into  separate  organs.  During 
the  growth  of  the  young  individual  these  are 
active  all  the  time.  It  is  a  mistake  to  think 
they  have  only  become  active  at  puberty. 
They  only  become  capable  of  producing 
active  sexual  cells  at  puberty,  but  long 
before  that  period  they  have  been  actively 
exercising  secret  chemical  functions  in  the 
body,  by  means  of  what  are  known  as  internal 
secretions,  which  are  poured  into  the  blood  and, 
being  carried  to  other  parts,  stimulate  these 
to  develop  in  definite  ways.  These  activities 
become  enhanced  as  puberty  approaches, 
and  such  internal  chemical  secretions  induce 
and  control  those  secondary  sexual  changes 
which  outwardly  differentiate  in  increasing 
degree  male  and  female  at  this  age. 

The  detailed  study  of  the  work  of  these 
various  co-ordinated  systems  is  the  domain 


232    ORIGIN  AND  NATURE  OF  LIFE 

of  the  physiologist  and  bio-chemist,  just 
as  the  study  of  their  derangements  forms  the 
province  of  bacteriologist  and  pathologist. 
Similarly  the  function  of  attempting  to  set 
right  or  repair  what  is  wrong,  rests  with 
physician  or  surgeon,  while  the  noblest  and 
as  yet  far  too  neglected  profession  of  all  is 
that  of  the  sanitarian  or  hygienist  who  is 
charged  with  preventing  affairs  from  going 
wrong.  When  our  social  senses  as  a  com- 
munity become  sufficiently  developed,  the 
sanitarian  turning  to  practical  account  the 
discoveries  of  the  others,  will  remove  for  us 
half  the  deaths  and  four-fifths  of  the  misery 
and  human  torture  which  to-day  we  supinely 
suffer. 

An  example  has  been  given  above  in  the 
case  of  the  reproductive  glands,  of  internal 
secretion.  This  is  one  of  the  most  wonderful 
discoveries  of  the  past  generation.  Although 
the  name  "  internal  secretion,"  and  the 
idea  of  the  course  of  events  was  introduced 
by  Brown-Sequard  in  France,  it  is  largely 
to  the  labours  of  Schafer  and  other  British 
physiologists,  such  as  Bayliss  and  Starling, 
that  we  owe  many  of  our  more  recent  advances 
of  knowledge  in  this  entrancingly  interesting 
field  of  investigation.  The  chemical  substances 
contained    in    the    internal    secretions    have 


THE    LIVING    ORGANISM        233 

been  named  hormones,  or  excitants,  by  Bayliss 
and  Starling.  In  certain  cases  the  chemists 
have  been  able  to  isolate  these  hormones, 
and  in  one  case  the  chemical  constitution  is 
known  and  the  substance  has  been  manu- 
factured artificially  in  the  laboratory.  In 
other  cases,  and  these  the  majority,  they 
are  as  yet  only  known  by  their  definite 
stimulating  action.  Quite  recently  it  has 
been  shown  that  bodies  similar  in  nature 
to  the  hormones  must  be  present  in  our  daily 
diet,  or  certain  typical  nutritional  diseases 
are  produced.  These  hormones  are  not  foods 
in  the  sense  of  being  necessary  to  provide 
energy  by  their  combustion  ;  they  are  only 
required  in  minute  amounts  as  excitants,  and 
in  their  absence  certain  very  specific  effects 
giving  the  clinical  symptoms  of  well-known 
diseases  appear.  In  a  liberal  and  mixed  diet 
all  the  necessary  hormones  required  from 
outside  are  contained.  But,  when  the  diet 
is  very  restricted,  such  as  the  rice  diet, 
used  by  the  Indian  coolie,  unless  the  thin 
brownish  layer  surrounding  the  inner  white 
part  of  the  rice  be  eaten  in  the  daily  diet, 
a  disease  with  marked  nervous  lesions  appears, 
called  beri-beri.  This  disease  long  puzzled 
medical  scientists,  but  it  is  now  clearly  shown 
to  be  caused  by  the  absence  from  the  diet 


234    ORIGIN  AND  NATURE  OF  LIFE 

of  an  excitant  contained  in  the  outer  layer 
of  the  rice.  Addition  of  this  cleaned-off 
material  in  small  amounts  prevents,  or 
relieves,  the  disease.  A  similar  condition  can 
be  produced  in  pigeons  or  fowls  fed  experi- 
mentally on  polished  rice,  (as  the  European 
product  with  the  outer  layer  removed  is 
called),  and  can  be  relieved  immediately  by 
small  amounts  of  extracts  of  the  rice  polish- 
ings.  Infantile  scurvy  is  an  example  of  an 
infantile  disease  of  our  own  country  produced 
by  restricted  diet  in  a  similar  manner.  As 
Barlow  first  showed,  it  may  rapidly  be  cured 
by  treatment  with  fresh  vegetables  such  as 
the  portion  of  potato  lying  below  the  rind,  or 
fresh  fruit  of  different  kinds.  There  is  little 
doubt  that  rickets  and  ship's  scurvy,  which 
are  now  being  investigated,  will  prove  diseases 
of  a  similar  kind. 

These  are  examples  of  external  hormones 
from  outside  the  body  required  in  the  daily 
food,  but  the  body-cells  within  require  to 
manufacture  internal  hormones,  to  establish 
important  correlating  functions.  If  the  ner- 
vous system  be  compared  to  the  telephonic 
or  telegraphic  system,  then  these  internal 
hormones  might  represent  the  postal  system 
of  the  body  by  which  one  part  is  kept  in  touch 
with  another.    The  chemical  intercommunica- 


THE    LIVING    ORGANISM        235 

tion  of  the  hormones  is  slower  than  that 
of  the  nervous  system,  but  more  detailed 
and  complete. 

There  exist  in  the  body  a  number  of  glands 
with  no  external  secretions  or  obvious  uses 
which  were  a  great  mystery  to  the  earlier 
anatomists  and  physiologists,  who  called  them 
"  bodies  "  or  "  capsules,"  and  left  the  matter 
at  that.  The  chief  of  these  are  called  the  supra- 
renals,  the  thyroids,  the  para- thyroids,  and 
the  pituitary.  It  is  now  known  that  these 
are  active  secreting  glands,  and  in  spite  of 
their  small  size  and  obscurity  of  function, 
are  absolutely  essential  to  the  life  of  the 
animal.  Their  removal  invariably  causes 
death  in  a  few  days  to  a  few  months'  time, 
and  any  marked  disturbance  of  their  function 
in  the  direction  either  of  excess  or  defect 
produces  profound  disease  often  of  a  fatal 
character. 

The  investigation  of  the  uses  of  the  supra- 
renals,  two  minute  glands  not  over  an  ounce 
in  weight,  lying  in  the  body  just  above  the 
kidneys,  but  in  no  functional  way  connected 
with  them,  may  be  taken  briefly  as  an  example. 
The  first  step  was  made  by  a  physician  of 
Guy's  Hospital,  named  Addison,  who  showed 
that  a  disease  since  called  Addison's  disease, 
was  related  to  a  diseased  condition  of  the 


236    ORIGIN  AND  NATURE  OF  LIFE 

suprarenals.  This  disease  shows  a  peculiar 
bronzing  of  the  skin  occurring  in  patches, 
and  is  accompanied  by  progressing  muscular 
weakness,  listlessness,  and  eventually  extreme 
lassitude.  It  is  invariably  fatal.  Next 
Brown-Sequard  showed  that  the  removal  of 
these  tiny  glands  always  led  to  fatal  results. 
This  was  confirmed  by  Schafer  and  other 
observers,  and  the  clinical  picture  is  that  of 
an  excessively  rapid  Addison's  disease.  The 
discovery  was  next  made  by  Schafer  and 
Oliver,  that  these  glands  are  constantly 
supplying  to  the  blood  a  chemical  hormone 
which  possesses  a  tonic  or  stimulating  action 
upon  the  heart  and  arteries,  particularly  the 
small  arteries,  or  arterioles,  leading  to  the 
capillaries.  The  substance  has  since  been 
isolated,  and  is  known  as  adrenalin.  It  has 
even  been  prepared  artificially,  and  its 
chemical  constitution  is  well  known.  When 
even  a  minute  amount  is  injected  into  a  vein, 
it  exercises  such  a  constricting  effect  upon  the 
muscular  coats  of  the  small  arteries  that  the 
bore  is  nearly  obliterated,  and  as  the  heart 
still  goes  on  pumping  with  even  greater  force, 
the  pressure  in  the  arteries  may  mount  to 
double  or  even  treble  its  usual  amount. 
It  is  obviously  the  absence  of  this  substance 
in  Addison's  disease  which  gives  rise  to  the 


THE    LIVING    ORGANISM        237 

symptoms  and  leads  ultimately  to  the  death 
of  the  patient.  It  is  truly  wonderful  that 
the  secretion  of  a  tiny  gland,  the  total  weight 
of  which  does  not  nearly  reach  one-thousandth 
part  of  the  body-weight,  should  produce  such 
a  prodigious  effect.  The  chemical  balance 
in  the  body  is  a  surpassingly  beautiful  and 
delicate  creation  ;  there  is  room  for  a  religion 
of  science  in  the  wonder  and  admiration  of 
these  things. 

As  an  additional  example  of  the  practical 
value  accruing  incidentally  from  scientific 
research,  it  may  be  mentioned  that  the  active 
principle  of  the  suprarenal  gland,  adrenalin, 
is  one  of  the  most  valued  aids  in  the  surgery 
of  the  nose  and  throat,  from  its  property  of 
stopping  bleeding  by  chemically  occluding 
small  arteries  in  situations  where  they  cannot 
be  reached  to  be  ligatured. 

The  thyroids  are  a  pair  of  glands  in  the 
neck  situated  on  each  side  of  the  larynx,  and 
of  about  the  same  size  as  the  suprarenal  s. 
In  the  normal  condition,  they  are  not  obvious, 
as  they  only  fill  up  the  rounding  of  the  contour 
on  each  side  of  what  is  popularly  known  as 
Adam's  apple  ;  but  disease  sometimes  enlarges 
them,  and  produces  a  goitre. 

If  these  glands  are  deficient  at  birth,  growth 
of  the  child  both  in  body  and  mind  becomes 


238    ORIGIN  AND  NATURE  OF  LIFE 

greatly  embarrassed,  and  the  product  is  a 
peculiar  type  of  dwarf  called  a  cretin,  found 
frequently  in  certain  Alpine  valleys.  Stray 
cretins  are  to  be  found  in  all  large  centres  of 
population,  and  in  a  typical  cases  there  can 
be  no  failure  of  recognition.  The  height  is 
stunted  down  to  four  feet  or  less,  the  head 
and  face  are  broad,  and  on  account  of  failure 
or  misplacement  of  the  natural  folds  of  the 
skin  the  features  are  lacking  in  expression. 
The  hair  and  skin  are  dry  and  lustreless,  and 
the  eyes  are  dull,  the  whole  indicating  even  to 
a  lay  person  a  condition  of  idiocy.  And  the 
undeveloped  mind  is  truly  indicated  by  these 
outward  appearances.  The  hands  even  are 
large  and  clumsy  in  shape,  and  the  fingers 
broad  and  stub-ended.  All  this  change  is 
produced  by  a  failure  in  the  secretion  of  a 
small  inconspicuous  gland  in  the  neck,  which 
in  a  grown  man  does  not  exceed  an  ounce 
in  weight.  Short  of  complete  cretinism, 
backwardness  in  intelligence  and  growth,  in 
many  of  our  mentally  defective  children  are 
due  to  diminished  thyroid  secretion,  and 
such  cases  show  wonderful  improvement  not 
only  in  growth  and  physical  vigour,  but  in 
mental  intelligence  also,  when  they  are  put 
upon  a  course  of  treatment  with  thyroid 
glands  of  the  sheep.     For  the  active  material 


THE   LIVING   ORGANISM        239 

does  not  undergo  destruction  in  the  process 
of  digestion.  Its  exact  chemical  nature  is 
unknown,  but  it  appears  to  be  a  colloidal 
substance  rich  in  iodine. 

When  disease  causes  the  secretion  to 
decrease  after  adult  life  is  reached,  as  it  often 
does,  dwarfing  cannot,  of  course,  be  produced, 
but  the  mental  symptoms  are  the  same.  The 
patient  loses  in  intelligence  and  becomes 
abnormally  forgetful,  so  that  no  continuous 
mental  process  can  be  carried  out.  The 
mind  becomes  inert,  the  heart-beat  is  slowed, 
the  face  becomes  vacant  and  expressionless, 
and  there  develops  a  striking  slowness  of 
thought  and  motion,  and  a  heavy,  slow  gait. 
Like  the  opposed  condition  of  goitre,  the 
disease,  known  as  myxcedema,  is  much  more 
prevalent  amongst  women  than  in  men. 
If  the  disease  be  not  promptly  treated  by 
administration  of  thyroid  gland,  the  mental 
symptoms  become  exaggerated,  the  patient 
becomes  irritable,  and  suspicious  of  the 
motives  of  relatives  or  attendants,  and  there 
may  be  hallucinations  leading  to  dementia. 
Feeding  on  thyroid  gland  is  the  only  really 
beneficial  treatment,  and  often  produces 
remarkable  results. 

Sir  William  Osier  describes  the  results 
of  thyroid  treatment  in  such  cases  as  follows  : 


240   ORIGIN  AND  NATURE  OF  LIFE 

*'  Our  art  has  made  no  more  brilliant  advance 
than  in  the  cure  of  these  disorders  due  to 
disturbed  function  of  the  thyroid  gland. 
That  we  can  to-day  rescue  children  otherwise 
doomed  to  helpless  idiocy ;  that  we  can  restore 
to  life  the  hopeless  victims  of  myxcedema,  is 
a  triumph  of  experimental  medicine  for 
which  we  are  indebted  very  largely  to  Sir 
Victor  Horsley  and  to  his  pupil,   Murray." 

"  The  results  as  a  rule  are  most  astounding — 
Unparalleled  by  anything  in  the  whole  range 
of  curative  measures.  Within  six  weeks 
a  poor,  feeble-minded,  toadlike  caricature 
of  humanity  may  be  restored  to  mental  and 
bodily  health.  The  skin  becomes  moist,  the 
pulse  rate  quickens,  and  the  mental  torpor 
lessens." 

In  the  disease  known  as  exophthalmic 
goitre,  the  symptoms  are  almost  the  exact 
antithesis  of  those  above  described,  and  the 
cause  is  excessive  secretion  of  the  active 
material  by  a  large  and  active  thyroid.  The 
patient  is  alert,  excitable,  and  vivacious  of 
mind,  the  heart-beat  is  rapid,  there  are 
fine  tremors  of  the  voluntary  muscles,  and 
the  whole  picture  is  one  of  nervous  over- 
excitement,  which  is  heightened  by  a  promi- 
nent bulging  forward  of  the  eyeballs  which 
gives  the  disease  its  name.     Somewhat  similar 


THE   LIVING   ORGANISM        241 

temporary  disturbances  may  be  induced  in 
normal  individuals,  by  excessive  treatment 
with  sheep's  thyroid  glands. 

These  results  show,  as  Gley,  a  prominent 
French  observer  on  the  subject,  remarks, 
that  "the  genesis  and  the  exercise  of  the 
highest  faculties  of  man  are  conditioned 
by  the  simple  chemical  action  of  a  product 
of  secretion,  a  fact  which  should  be  borne  in 
mind  by  psychologists." 

The  pituitary  is  a  still  smaller  gland  than 
either  suprarenals  or  thyroids,  and  is  a  single 
gland  attached  to  the  base  of  the  brain.  Its 
hypertrophy  during  youth  leads  to  giantism, 
and  most  giants  exhibited  at  "  shows,"  on 
examination  after  death  show  hypertrophied 
pituitaries.  When  the  hypertrophy  occurs  after 
growth  of  the  skeleton  is  completed,  the  result 
is  a  disease  showing  remarkable  overgrowth  of 
certain  bones  only,  known  as  acromegaly.  The 
overgrowth  occurs  chiefly  in  the  bones  of  the 
hands  and  feet,  and  the  bones  of  the  face, 
especially  the  lower  jaw,  producing  a  remark- 
able and  unmistakable  appearance.  Giantism 
is  a  somewhat  rare  disease,  but  cases  in 
elderly  persons  of  the  partial  form  are  not  so 
infrequent.  Small  as  the  pituitary  gland  is,  it 
is  composed  of  two  parts  of  quite  different 
function.    It   is   only   the   anterior   portion 

Q 


242   ORIGIN  AND  NATURE  OF  LIFE 

which  is  concerned  in  regulating  osseous 
growth,  the  posterior  portion  secretes  a 
hormone  which  has  a  somewhat  similar  action 
to  the  suprarenal,  but  feebler  and  differently 
evoked,  As  has  recently  been  shown  by 
Schafer,  it  also  stimulates  the  secretion 
both  of  the  kidney  and  of  the  active  mammary 
gland. 

In  addition  to  these  remarkable  chemical 
sympathies  of  the  ductless  glands,  other 
glands  in  the  body  possessed  of  ducts  such  as 
the  pancreas,  which  produces  a  powerful 
digestive  secretion,  also  are  found  to  possess 
internal  secretion.  Thus,  ligature  of  the 
duct  of  the  pancreas  so  as  to  stop  the  action 
of  its  secretion,  does  not  cause  death.  The 
work  of  digestion  is  performed  vicariously 
by  other  secretions.  As  much  as  two-thirds 
even  of  the  gland  and  the  duct  may  be 
removed  without  producing  serious  symptoms. 
But,  if  the  remaining  third  be  removed, 
or  if  the  total  gland  has  been  removed  in  the 
first  instance,  then  death  within  two  or  three 
weeks,  from  the  severest  form  of  diabetes, 
is  the  invariable  result. 

In  severe  diabetes  in  man,  the  pancreas 
is  often  found  diseased,  although  milder 
diabetes  may  result  from  other  causes. 

These  results  demonstrate  that  the  pancreas 


CYCLIC    ACTIVITIES    OF   LIFE     243 

in  addition  to  its  external  obvious  secretion 
which  it  pours  into  the  intestine,  possesses 
a  secret  internal  secretion  which  it  pours 
into  the  blood  for  the  regulation  of  carbo- 
hydrate exchanges  in  the  body. 

These  instances  may  suffice  to  demonstrate 
the  wealth  of  chemical  sympathies  existing 
between  the  huge  nations  of  living  units 
of  different  types  which  constitute  our  bodies, 
and  the  delicacy  of  structure  can  be  appre- 
ciated which  makes  such  highly  specific 
reactions  possible.  The  whole  subject  is 
modern,  and  is  as  yet  by  no  means  exhausted. 


CHAPTER   X 

CYCLIC   ACTIVITIES    OF   LIFE  : 
WAKING      AND      SLEEPING  I        FATIGUE      AND 
RECUPERATION 

The  living  cell  may  be  regarded,  from  the 
physico-chemical  point  of  view,  as  a  peculiar 
energy-transformer,  through  which  a  con- 
tinually varying  flux  of  energy  ceaselessly 
goes  on,  and  the  whole  life  of  the  cell  is  an 
expression  of  variations  and  alternations  in 
rates  of  flow  of  energy,  and  of  swings  in  the 
balance  between  various  forms  of  energy. 


244    ORIGIN  AND  NATURE  OF  LIFE 

Just  as  in  the  production  of  electrical 
energy  by  means  of  a  dynamo,  which  is  an 
energy-transformer,  there  is  a  conversion  of 
mechanical  energy  into  electrical  energy, 
and  this  electrical  energy  shows  its  peculiar 
properties  by  which  electricity  is  characterized 
and,  in  turn,  according  to  the  transformer 
through  which  it  is  passed,  may  be  turned 
into  various  other  forms  of  energy,  such  as 
mechanical  energy,  magnetic  energy,  heat, 
light,  or  chemical  energy,  so  chemical  energy 
in  the  living  cell  is  converted  by  the  colloidal 
structure  into  the  peculiar  type  of  energy 
characteristic  of  living  organisms,  which  has 
been  called  biotic  energy,  and  this  biotic 
energy  manifesting  its  own  specific  properties 
in  the  process,  is  convertible  into  mechanical 
energy,  electrical  energy,  heat  energy,  or 
chemical  energy. 

All  energy  transformations  are  oscillatory 
or  phasic  in  their  discharges.  Each  energy 
transformer  has  its  phasic  period,  or  revolution 
time,  in  which  it  passes  through  a  cycle  or 
oscillation.  This  is  equally  true  of  the  living 
energy-transformers  or  living  cells,  and  the 
period  varies  from  one  type  of  cell  to  another. 
As  a  rule,  being  dependent  as  has  been  seen 
upon  the  more  complex  character  of  the 
constituent  colloids,  the  period  of  oscillation 


CYCLIC   ACTIVITIES   OF   LIFE    245 

is  generally  slower  in  organic  forms  of  kinetic 
energy  than  in  inorganic  forms.  As  a  result 
the  phasic  discharges  become  more  obvious 
to  the  senses,  and  there  is  nothing  more 
beautiful  than  to  watch  the  swing  to  and  fro 
in  measured  rhythm  of  the  various  life- 
processes.  As  long  as  life  lasts  there  is  no 
complete  cessation  in  the  flow  of  energy,  but 
always  in  all  living  things  there  are  alternating 
periods  of  activity  and  repose,  of  waking  and 
sleeping,  of  action  and  reaction,  of  freshness 
and  fatigue. 

Another  important  point  is  that  in  these 
slower  surgings  of  the  life-process,  the  short 
simple  cycle  of  inorganic  nature  is  often 
replaced  by  a  long  procession  or  sequence  of 
events  in  definite  order,  and  with  many 
members  such  as  is  never  seen  in  absence 
of  life.  The  development  of  man,  or  a  higher 
mammal,  from  the  ovum  is  one  example ;  the 
ordered  sequence  of  the  outburst  of  seasonal 
life  in  the  cycle  of  the  year  is  another ;  and 
countless  examples  of  such  lengthy  cycles 
where  one  energy  exchange  is  contingent 
upon  and  sequent  in  time  to  another,  occur 
in  the  daily  lives  of  higher  plant  and  animal 
individuals. 

Although  the  cyclic  processes  of  life  demon- 
strate a  longer  time-interval  throughout,  as 


246    ORIGIN  AND  NATURE  OF  LIFE 

compared  with  inorganic  nature,  they  vary 
amongst  themselves  from  a  period  of  several 
years,  as  in  the  growth  to  maturity  of  the 
human  individual,  to  a  minute  fraction  of  a 
second,  as  in  the  time  of  passage  of  a  nervous 
impulse  which  occupies  not  more  than  the 
one  ten-thousandth  part  of  a  second. 

Some  of  the  cyclic  periods  of  living  cells  are 
so  short  that  their  truly  cyclical  character, 
and  the  nature  of  the  alternations,  have  been 
missed  or  mis-stated  by  physiologists  in  the 
past.  Conspicuous  examples  of  this  are  to  be 
found  in  regard  to  nervous  activity  and  the 
rhythmic  contractions  of  cardiac  muscle. 
In  nearly  every  current  textbook  of  physiology 
the  statement  will  be  found,  followed  by 
elaborate  proofs,  that  nerve  and  heart- 
muscle  cannot  be  fatigued,  or  are  indefatigable, 
as  it  is  called.  The  true  statement  which 
ought  to  replace  this  is,  that  the  cycle  of 
fatigue  and  recuperation  is  so  rapid  that 
fatigue  and  recovery  occur  between  each 
heart-beat,  or  each  nervous  impulse. 

It  has  been  shown  by  Schafer  that  the 
nervous  impulse  sent  out  to  the  voluntary 
muscles  is  not  continuous,  but  consists  of  a 
series  of  impulses  at  the  rate  of  ten  to  twelve 
per  second.  Now  the  period  of  passage  of  each 
of  these  over  any  given  portion  of  nerve  is 


CYCLIC   ACTIVITIES   OF   LIFE     247 

only  one  ten-thousandth  of  a  second,  and  on 
adding  up  the  number  of  impulses  in  a  second, 
it  is  obvious  that  at  most  the  tissue  is  only 
active  for  twelve  ten-thousandths  of  a  second 
in  each  second,  or  for  about  0.12  per  cent,  of 
the  total  time.  There  is  thus  sufficient  inter- 
val for  recuperation  between  each  period  of 
activity.  Even,  when  an  electric  current  of 
1000  shocks  per  second  is  used  as  a  stimulus, 
there  is  ample  time  between  each  stimulation 
for  recuperation.  At  a  much  higher  rate  of 
stimulation  than  this  the  nerve  tissue  solves 
the  problem  by  ceasing  to  respond.  A  strong 
enough  current  to  light  up  powerful  electric 
lamps  can  be  sent  through  the  human  body 
if  the  electric  oscillations  exceed  30,000  to 
40,000  per  second,  without  causing  any 
effect  upon  the  muscles  or  nerves. 

The  rate  is  much  slower  for  the  contractions 
of  heart  muscle,  although  still  very  rapid 
amongst  biological  phases.  As  a  result, 
the  sequence  of  events  becomes  more  obvious. 
Just  after  each  contraction,  so  far  from  not 
being  fatigued,  the  heart  muscle  is  so  com- 
pletely fatigued  that  it  has  what  is  called  a 
refractory  period.  It  relaxes  and  cannot  be 
caused  to  contract  even  by  a  strong  external 
stimulus.  It  rapidly,  however,  loses  the 
products  of  its  fatigue,  its  colloids  re-arrange 


248   ORIGIN  AND  NATURE  OF  LIFE 

their  molecules  with  great  speed,  and  its 
energy  charges  accumulate  so  rapidly  that 
soon  it  passes  into  another  phase  of  activity 
automatically  without  any  stimulus  from 
without. 

The  tissues  of  nerve  and  heart  muscle 
must  inevitably  be  arranged  on  the  principle 
of  such  short  periods  of  fatigue  and  recupera- 
tion. It  would  be  impossible  for  them  to 
possess  the  longer  periods  of  other  tissues, 
or  recuperation,  by  sleep,  of  the  body  as  a 
whole  would  become  impossible.  During  the 
repose  of  the  body  as  a  whole,  respiration 
and  circulation  must  be  continued  ;  cessation 
of  either  for  so  short  a  time  even  as  two 
minutes  would  lead  to  death  of  the  whole 
organism.  So  these  shorter  shifts  of  labour 
and  rest  become  developed  in  the  balanced 
system  of  their  colloids.  Apart  from  the 
changed  time  interval,  however,  the  main 
features  of  the  cycle  are  the  same.  Waste 
products  are  produced  in  the  active  period, 
cause  fatigue,  are  discharged;  and  in  the 
resting  period,  fresh  molecular  arrangements 
are  made  and  energy  stored  for  the  next  active 
period.  In  the  rhythmically  active  heart 
muscle  the  balance  of  nutrient  matter,  of  the 
oxygen  used  for  combustion,  and  of  carbon- 
dioxide  formed  in  combustion,  is  set  with  the 


CYCLIC    ACTIVITIES    OF   LIFE     249 

utmost  delicacy ;  it  is  only  within  fairly 
close  limits  that  the  rapid  to  and  fro  swing  is 
possible.  Appreciable  variation  in  any  one 
of  these  factors,  or  the  presence  of  traces 
only  of  various  drugs  such  as  chloroform,  or 
various  cardiac  tonics,  soon  slow  or  hasten 
the  beat,  and  a  little  additional  excess  (or 
defect  of  the  normal  constituents)  stills  the 
organ  completely,  or  sends  it  into  delirium 
also  ending  in  stoppage. 

Other  more  slowly  oscillating  living  systems 
allow  greater  variations,  but  each  has  its 
limits  which  must  not  be  surpassed.  Fatigue 
after  daily  work  and  the  nightly  recuperation 
in  sleep  are  examples  of  the  effects  of  slower 
accumulation  of  waste  products.  The  elimi- 
nation of  these  fatigue  products,  and  the 
building  up  of  fresh  reserve  stores  within  the 
cells  during  sleep  complete  the  cycle. 

Phasic  or  rhythmic  activity  in  some  degree 
or  other,  and  with  widely  varying  rates, 
is  inherent  in  the  various  crystallo-colloids 
of  all  living  matter.  It  is  seen  in  the  un- 
striated,  or  involuntary,  muscle  of  all  parts 
of  the  body,  such  as  alimentary  canal,  bladder, 
uterus,  spleen,  arterial  walls,  everywhere 
with  varying  rhythm  in  different  situations, 
according  to  development  and  requisite 
physiological  functions.     It  is  seen  in  all  the 


250   ORIGIN  AND  NATURE  OF  LIFE 

secreting  glands,  where  the  precursors  of  the 
secretion  accumulate  during  rest,  and  are 
discharged  on  activity,  leading  to  exhaustion 
which  ushers  in  a  new  period  of  rest.  Some 
external  stimulus  forming  an  act  in  a  greater 
cycle  in  the  body  usually  wakes  the  gland 
into  activity,  but,  failing  this,  if  the  time- 
interval  becomes  too  long,  it  automatically 
passes  into  activity  and  discharges  itself. 

A  most  interesting  and  beautiful  example 
of  such  a  rhythm  dependent  upon  external 
stimulation  under  normal  conditions,  but 
capable  of  becoming  automatic  in  absence 
of  the  wonted  stimulus,  or  its  delayed  arrival 
beyond  the  accustomed  time,  is  found  in  the 
case  of  the  phosphorescent  organisms  so 
abundant  in  our  seas  especially  in  the  autumn 
months. 

It  might  be  supposed  at  first  thought  that 
these  phosphorescent  organisms  are  not  ob- 
served to  emit  light  during  the  day  because  of 
the  presence  of  sunlight,  and  that  if  taken  into 
a  dark  room,  such  as  is  used  foi  photographic 
purposes,  they  would  be  found  to  phos- 
phoresce just  as  brilliantly  as  at  night. 
Such  is,  however,  not  the  case,  not  a  spark 
can  be  elicited  from  them  even  by  vigorous 
shaking,  so  long  as  there  is  daylight  in  the 
outer    world.     But    if    one    stands    by    and 


CYCLIC    ACTIVITIES    OF   LIFE     251 

watches  in  the  dark  room,  as  twilight  is 
falling  outside,  although  the  organisms  have 
not  been  exposed  to  light  all  day,  one  observes 
the  little  lamps  light  up  and  flash  out  one 
by  one  like  coruscating  diamonds  in  the 
darkness,  till  the  whole  dish  is  studded  with 
flashing  and  disappearing  light,  a  glorious 
sight  in  the  darkness  and  stillness. 

At  the  daybreak,  the  series  of  changes 
are  the  reverse  of  those  witnessed  at  dusk  ; 
if  the  dish  containing  the  organisms  be 
observed  in  the  dark  room  about  an  hour 
before  sunrise,  it  will  be  seen  that  at  first 
the  organisms  are  still  flashing  out  brilliantly, 
but  about  half  an  hour  before  sunrise,  the 
number  of  flashes  begins  to  diminish  rapidly ; 
at  sunrise  there  are  hardly  any  showing,  and 
half  an  hour  later  even  violent  stirring  will 
not  produce  a  single  sparkle.  The  most 
remarkable  thing  of  all  is  that  this  regular 
daily  phasic  action  is  kept  up  for  as  long  as 
fourteen  days,  by  which  time  the  organisms 
have  perished  in  captivity.  Regularly  every 
evening  the  lights  come  out,  and  as  regularly 
every  morning  they  are  extinguished,  although 
all  the  intervening  time  the  tiny  living 
creatures  have  been  kept  in  darkness. 

A  similar  diurnal  rhythm  has  been  observed 
for  shorter  periods  in  plant  leaves  which  alter 


252    ORIGIN  AND  NATURE  OF  LIFE 

their  position  at  day  and  night,  when  the 
plants  have  been  kept  in  darkness. 

The  whole  of  the  physiological  and  chemical 
processes  of  reproduction  in  the  mammalia 
illustrate  the  phasic  activity  of  living  matter 
in  a  most  striking  fashion.  In  the  lower 
mammalia,  there  are  the  seasonal  periods  of 
activity  in  ordered  sequence,  the  whole 
reproductive  system  passes  into  excitement 
in  its  different  parts,  showing  the  pre-cestral 
period,  then  the  active  mental  and  other 
excitement  of  the  oestrus,  followed  in  turn 
by  the  post-cestral  period.  In  the  human 
species,  the  cycle  is  even  more  regular,  and  is 
more  frequently  recurrent. 

During  gestation  the  same  phasic  intervals 
are  seen,  as  also  in  post-natal  growth,  and 
throughout  the  whole  life  of  the  individual 
the  same  phasic  repetition  is  seen  constituting 
the  great  cycle  of  life. 

In  the  invertebrata  cyclic  processes  are 
often  shown  in  a  most  remarkable  way. 
Mention  need  only  be  made  of  the  metamor- 
phoses of  the  insecta,  and  the  wonderful 
developmental  history  of  the  echinodermata 
and  mollusca.  In  protozoa  also  there  are  the 
alternations  of  sexual  with  asexual  (or  parthe- 
nogenetic)  reproduction  occurring  spontaneous- 
ly, or  in  response  to  environmental  changes. 


CYCLIC   ACTIVITIES    OF   LIFE     253 

The  seasonal  variations  in  the  life  cycle 
of  plants  yield  additional  examples,  and  a 
great  correlation  of  many  life  cycles  involving 
several  different  species  of  plants  and  animals 
in  harmonious  sequence,  is  observable  in  the 
order  of  appearance  of  the  minute  creatures, 
in  pond  and  ocean,  and  upon  earth,  with  the 
coming  of  the  spring. 

Here,  then,  we  stand  at  the  end  of  our 
review  of  inorganic  and  organic  evolution, 
and  of  the  origin  and  nature  of  life.  There  is 
continuity  and  consistency  in  it  all ;  there 
is  beauty  in  it  and  design  in  it. 

There  is  a  scheme  in  it  all  and  an  eternal 
purpose  which  is  ever  progressing.  It  means 
something  that  this  much  has  been  revealed 
to  us,  and  having  once  seen  it  there  comes  a 
touch  of  illumination  and  faith,  that  kindles 
something  sacred  within  the  mind  akin  to 
reverence  and  love.  One  must  needs  work 
for  the  highest  and  for  more  knowledge  of  this 
revelation,  whatever  the  future  may  hold  in 
store,  for  we  do  not  now  know  how  more  and 
more  glorious  things  may  yet  be. 

Liverpool,  November  1st,  1912. 


BIBLIOGRAPHY 

The  following  volumes  in  the  Home  University  Library, 
give  more  detail  upon  subjects  which  have  only  been 
treated  in  the  present  volume  incidentally  to  its  main 
theme : — Matter  and  Energy :  Frederick  Soddy.  The 
Making  of  the  Earth  :  J.  W.  Gregory.  Evolution  :  Patrick 
Geddes  and  J.  Arthur  Thomson.  Introduction  to  Science  / 
J.  Arthur  Thomson.  The  Principles  of  Physiology :  J.  G. 
McKendrick. 

Volumes  bearing  on  the  subjects  of  the  several  chapters 
(some  of  which  have  been  consulted  by  the  author  in 
preparation)  are  as  follows : — Arrhenius,  SvaNte  :  Worlds 
in  the  Making.  Translated  by  H.  Boms.  1908,  Harper 
Bros.  Bastian,  Charlton:  The  Origin  of  Life.  1911, 
Watts  &  Co.,  London.  Lockyer,  Sir  Norman  :  Inorganic 
Evolution  as  studied  by  Spectrum  Analysis.  1908, 
Macmillan  &  Co.,  London.  Lodge,  Sir  Oliver:  Electrons. 
1906,  George  Bell  &  Co.  Macfie,  Ronald  Campbell: 
Science,  Matter,  and  Immortality.  1909,  Williams  & 
Norgate,  London.  Moore,  Benjamin  :  Articles  in 
"Recent  Advances  in  Physiology  and  Bio-Chemistry," 
1906 ;  and  "  Further  Advances  in  Physiology  and  Bio- 
Chemistry,"  1908.  Edited  by  Leonard  Hill,  Arnold, 
London.  Thomson,  J.  Arthur:  The  Bible  of  Nature. 
1911,  T.  &  T.  Clark,  Edinburgh.  Thomson,  Sir  J.  J. : 
The  Corpuscular  Theory  of  Matter.  1907,  Constable  &  Co. 
Verworn,  Max  :  General  Physiology.  An  Outline  of  the 
Science  of  Life,  translated  by  Frederic  S«  Lee,  1899, 
Macmillan,  London. 

The  original  articles  by  Thomas  Graham  on  "  Colloids  M 
are  to  be  found  in  Philosophical  Transactions  of  Royal 
Society,  London,  1861,  Vol.  154,  p.  183  ;  and  Proceedings 
of  Royal  Society,  London,  1804,  Vol.  xiii.,  p,  335, 
254 


INDEX 


Addison,  235 

Adrenalin,  236 

Adsorption,  125 

Affinity,  78,  84,  123 

Affinity,  molecular,  124  et  seq. 

Amino-acids,  117 

Argon,  50 

Aristotle,  164 

Arrhenius,  173 

Atoms,  27  et  seq. 

Bacteria,  178,  214 
Bastian,  193  et  seq. 
Bayliss,  232 
Beri-beri,  233 
Biotic  Energy,  225,  226 
Brown-Sequard,  232 
Buffon,  167 

Carbohydrates,  108 

Carbon  atom,  92  et  seq. 

Cell,  43,  218  et  seq. 

Chlorophyll,  179  et  seq. 

Chromosomes,  221 

Collie,  60 

Colloids,  18,  43,  121,  123   et  seq., 

139,  141 
Cosmozoa,  172 
Cretin,  238 
Crookes,  175 
Crystallo-colloids,  154 
Crystalloids,  129  et  seq. 
Cyclic   alternation,    143,    243    et 

seq. 

Dalton,  39 
Darwin,  162 
Diphtheria,  205 

Electrons,  27  et  seq.,  48,  51,  61 
Elements,  42 
Elixir  vitce,  161 
Energy,  28,  34  et  seq.,  79 
Enzymes,  146,  186 
Equilibrium,  Metastable,  188 
Ether,  luminiferous,  46,  58,  73 


Fatigue,  246  et  seq. 
Fats,  110 
Fischer,  119 

Gley,  241 

Graham,  18,  124,  149,  152,  156 

Haemoglobin,  56 
Harvey,  30 
Heart-beat,  155 
Helium,  50,  51 
Helmholtz,  172 
Hormones,  201 
Horsley,  240 
Huxley,  193 
Hydrogel,  139 
Hydrosol,  139 

Imagination,  Value  of,  26 

Kelvin,  172 

Lability,  121 

Law  of  Complexity,  188 

Law,  Periodic,  41 

Leucocytes,  207 

Lister,  161 

Lockyer,  60,  64,  73 

Macaulay,  8 
Materialism,  23 
Micro-cocci,  203,  214 
Murray,  240 
Mythology,  24,  27 

Nageli,  173 
Nebulae,  55 
Needham,  167 
Nervous  system,  45 
Newton,  40 
Nucleus,  220 

Oliver,  236 
Osier,  239 

Panspermia,  172 


255 


256 


INDEX 


Pasteur,  161  et  teq. 
Philosopher's  stone,  160 
Phosphorescence,  250 
Pouchet,  169 
Proteins,  114 

Proto-elements,  54,  64,  76 
Protozoa,  190 

Radio-activity,  17,  33,  47,  57,  226 

Radium,  41,  226 

Ramsay,  50,  59,  60 

Rayleigh,  50 

Redi,  165,  166 

Richter,  173 

Ringer,  143 

Saturation,  Atomic,  132 

Schafer,  163,  175,  236,  242,  246 

Sherrington,  227 

Soddv,  43,  60 

Solution  aggregate,  138,  140 

Spallanzani,  165,  167 


Spectroscopy,  41,  52,  73 

Spontaneous  generation,  162  et  seq. 

Starling,  232 

Stars,  Classification  of,  74 

Sunlight,  113,  178 

Syphilis,  216 

Thales,  163 
Toxins,  204 
Transformers,  44,  177,  183,  224, 

243 
Tuberculosis,  206 

Uranium,  41,  47,  226 

Valency,  Atomic,  78  et  seq.,  88 
Valency,  Molecular,  126 
Valisneri,  165,  166 
Van  Helmont,  163 
Voltaire,  169 

X-rays,  38,  47,  61,  77 


